From: Adam Dickmeiss Date: Mon, 8 Apr 2002 19:52:29 +0000 (+0000) Subject: More Docbook doc updates X-Git-Tag: CHANGELOG~3 X-Git-Url: http://jsfdemo.indexdata.com/cgi-bin?a=commitdiff_plain;h=dd8372e3f27c68a0410f13044dd184ccde8ca243;p=idzebra-moved-to-github.git More Docbook doc updates --- diff --git a/configure.in b/configure.in index 3007b3c..b9ba2f9 100644 --- a/configure.in +++ b/configure.in @@ -1,5 +1,5 @@ dnl Zebra, Index Data Aps, 1994-2002 -dnl $Id: configure.in,v 1.35 2002-04-08 13:50:12 adam Exp $ +dnl $Id: configure.in,v 1.36 2002-04-08 19:52:29 adam Exp $ dnl AC_INIT(include/zebraver.h) AC_MSG_CHECKING(for package) @@ -194,5 +194,6 @@ AC_OUTPUT([ doc/zebra.xml doc/zebrahtml.dsl doc/zebraprint.dsl + doc/zebraphp.dsl test/Makefile test/gils/Makefile test/usmarc/Makefile test/api/Makefile ]) diff --git a/doc/Makefile.am b/doc/Makefile.am index c10e249..d3c5fdc 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -1,24 +1,29 @@ -## $Id: Makefile.am,v 1.4 2002-04-08 13:50:13 adam Exp $ +## $Id: Makefile.am,v 1.5 2002-04-08 19:52:29 adam Exp $ docdir=$(pkgdatadir)/doc doc_data = zebra.pdf zebra.html SUPPORTFILES = zebrahtml.dsl.in zebraprint.dsl.in xml.dsl +XMLFILES=administration.xml installation.xml introduction.xml \ + license.xml indexdata.xml EXTRA_DIST = zebra.sgml gils.sgml zebra.txt zebra.ps zebra.html \ zebra-1.html zebra-2.html zebra-3.html zebra-4.html zebra-5.html \ zebra-6.html zebra-7.html zebra-8.html zebra-9.html \ zebra.xml.in $(SUPPORTFILES) +zebra.html: zebra.xml $(XMLFILES) + jade -E14 -d zebrahtml.dsl -t sgml xml.dcl zebra.xml + +zebra.php: zebra.xml $(XMLFILES) + jade -E14 -d zebraphp.dsl -t sgml xml.dcl zebra.xml + zebra.pdf: zebra.xml jade -E14 -d zebraprint.dsl -t tex xml.dcl zebra.xml pdfjadetex zebra.tex pdfjadetex zebra.tex pdfjadetex zebra.tex -zebra.html: zebra.xml - jade -E14 -d zebrahtml.dsl -t sgml xml.dcl zebra.xml - gils.txt: gils.sgml sgml2txt -f gils.sgml diff --git a/doc/administration.xml b/doc/administration.xml index ccb156f..fd1e8f4 100644 --- a/doc/administration.xml +++ b/doc/administration.xml @@ -1,3430 +1,3484 @@ -Quick Start - - -In this section, we will test the system by indexing a small set of sample -GILS records that are included with the software distribution. Go to the -test/gils subdirectory of the distribution archive. There you will -find a configuration -file named zebra.cfg with the following contents: - - -# Where are the YAZ tables located. -profilePath: ../../../yaz/tab ../../tab - -# Files that describe the attribute sets supported. -attset: bib1.att -attset: gils.att - - - - - -Now, edit the file and set profilePath to the path of the -YAZ profile tables (sub directory tab of the YAZ distribution -archive). - - - -The 48 test records are located in the sub directory records. -To index these, type: - - -$ ../../index/zebraidx -t grs.sgml update records - - - - - -In the command above the option -t specified the record -type — in this case grs.sgml. The word update followed -by a directory root updates all files below that directory node. - - - -If your indexing command was successful, you are now ready to -fire up a server. To start a server on port 2100, type: - - -$ ../../index/zebrasrv tcp:@:2100 - - - - - -The Zebra index that you have just created has a single database -named Default. The database contains records structured according to -the GILS profile, and the server will -return records in either either USMARC, GRS-1, or SUTRS depending -on what your client asks -for. - - - -To test the server, you can use any Z39.50 client (1992 or later). For -instance, you can use the demo client that comes with YAZ: Just cd to -the client subdirectory of the YAZ distribution and type: - - - - - -$ client tcp:localhost:2100 - - - - - -When the client has connected, you can type: - - - - - -Z> find surficial -Z> show 1 - - - - - -The default retrieval syntax for the client is USMARC. To try other -formats for the same record, try: - - - - - -Z>format sutrs -Z>show 1 -Z>format grs-1 -Z>show 1 -Z>elements B -Z>show 1 - - - - - -NOTE: You may notice that more fields are returned when your -client requests SUTRS or GRS-1 records. When retrieving GILS records, -this is normal - not all of the GILS data elements have mappings in -the USMARC record format. - - - -If you've made it this far, there's a good chance that -you've got through the compilation OK. - - + Quick Start + + + In this section, we will test the system by indexing a small set of sample + GILS records that are included with the software distribution. Go to the + test/gils subdirectory of the distribution archive. + There you will find a configuration + file named zebra.cfg with the following contents: + + + # Where are the YAZ tables located. + profilePath: ../../../yaz/tab ../../tab + + # Files that describe the attribute sets supported. + attset: bib1.att + attset: gils.att + + + + + Now, edit the file and set profilePath to the path of the + YAZ profile tables (sub directory tab of the YAZ + distribution archive). + + + + The 48 test records are located in the sub directory + records. To index these, type: + + + $ ../../index/zebraidx -t grs.sgml update records + + + + + In the command above the option -t specified the record + type — in this case grs.sgml. + The word update followed + by a directory root updates all files below that directory node. + + + + If your indexing command was successful, you are now ready to + fire up a server. To start a server on port 2100, type: + + + $ ../../index/zebrasrv tcp:@:2100 + + + + + + The Zebra index that you have just created has a single database + named Default. + The database contains records structured according to + the GILS profile, and the server will + return records in either either USMARC, GRS-1, or SUTRS depending + on what your client asks for. + + + + To test the server, you can use any Z39.50 client (1992 or later). + For instance, you can use the demo client that comes with YAZ: Just + cd to the client subdirectory of the YAZ distribution + and type: + + + + $ ./yaz-client tcp:localhost:2100 + + + + + When the client has connected, you can type: + + + + + + Z> find surficial + Z> show 1 + + + + + The default retrieval syntax for the client is USMARC. To try other + formats for the same record, try: + + + + Z>format sutrs + Z>show 1 + Z>format grs-1 + Z>show 1 + Z>elements B + Z>show 1 + + + + + You may notice that more fields are returned when your + client requests SUTRS or GRS-1 records. When retrieving GILS records, + this is normal - not all of the GILS data elements have mappings in + the USMARC record format. + + + + If you've made it this far, there's a good chance that + you've got through the compilation OK. + + -Administrating Zebra - - -Unlike many simpler retrieval systems, Zebra supports safe, incremental -updates to an existing index. - - - -Normally, when Zebra modifies the index it reads a number of records -that you specify. -Depending on your specifications and on the contents of each record -one the following events take place for each record: - - - -Insert - - -The record is indexed as if it never occurred -before. Either the Zebra system doesn't know how to identify the record or -Zebra can identify the record but didn't find it to be already indexed. - - - - -Modify - - -The record has already been indexed. In this case -either the contents of the record or the location (file) of the record -indicates that it has been indexed before. - - - - -Delete - - -The record is deleted from the index. As in the -update-case it must be able to identify the record. - - - - - - - -Please note that in both the modify- and delete- case the Zebra -indexer must be able to generate a unique key that identifies the record in -question (more on this below). - - - -To administrate the Zebra retrieval system, you run the -zebraidx program. This program supports a number of options -which are preceded by a minus, and a few commands (not preceded by -minus). - - - -Both the Zebra administrative tool and the Z39.50 server share a -set of index files and a global configuration file. The -name of the configuration file defaults to zebra.cfg. -The configuration file includes specifications on how to index -various kinds of records and where the other configuration files -are located. zebrasrv and zebraidx must -be run in the directory where the configuration file lives unless you -indicate the location of the configuration file by option --c. - - - -Record Types - - -Indexing is a per-record process, in which either insert/modify/delete -will occur. Before a record is indexed search keys are extracted from -whatever might be the layout the original record (sgml,html,text, etc..). -The Zebra system currently supports two fundamantal types of records: -structured and simple text. -To specify a particular extraction process, use either the -command line option -t or specify a -recordType setting in the configuration file. - - - - - -The Zebra Configuration File - - -The Zebra configuration file, read by zebraidx and -zebrasrv defaults to zebra.cfg unless specified -by -c option. - - - -You can edit the configuration file with a normal text editor. -parameter names and values are seperated by colons in the file. Lines -starting with a hash sign (#) are treated as comments. - - - -If you manage different sets of records that share common -characteristics, you can organize the configuration settings for each -type into "groups". -When zebraidx is run and you wish to address a given group -you specify the group name with the -g option. In this case -settings that have the group name as their prefix will be used -by zebraidx. If no -g option is specified, the settings -with no prefix are used. - - - -In the configuration file, the group name is placed before the option -name itself, separated by a dot (.). For instance, to set the record type -for group public to grs.sgml (the SGML-like format for structured -records) you would write: - - - - - -public.recordType: grs.sgml - - - - - -To set the default value of the record type to text write: - - - - - -recordType: text - - - - - -The available configuration settings are summarized below. They will be -explained further in the following sections. - - - - - - -group.recordType[.name] - - -Specifies how records with the file extension name should -be handled by the indexer. This option may also be specified -as a command line option (-t). Note that if you do not -specify a name, the setting applies to all files. In general, -the record type specifier consists of the elements (each -element separated by dot), fundamental-type, -file-read-type and arguments. Currently, two -fundamental types exist, text and grs. - - - - -group.recordId - - -Specifies how the records are to be identified when updated. See -section . - - - - -group.database - - -Specifies the Z39.50 database name. - - - - -group.storeKeys - - -Specifies whether key information should be saved for a given -group of records. If you plan to update/delete this type of -records later this should be specified as 1; otherwise it -should be 0 (default), to save register space. See section -. - - - - -group.storeData - - -Specifies whether the records should be stored internally -in the Zebra system files. If you want to maintain the raw records yourself, -this option should be false (0). If you want Zebra to take care of the records -for you, it should be true(1). - - - - -register - - -Specifies the location of the various register files that Zebra uses -to represent your databases. See section -. - - - - -shadow - - -Enables the safe update facility of Zebra, and tells the system -where to place the required, temporary files. See section -. - - - - -lockDir - - -Directory in which various lock files are stored. - - - - -keyTmpDir - - -Directory in which temporary files used during zebraidx' update -phase are stored. - - - - -setTmpDir - - -Specifies the directory that the server uses for temporary result sets. -If not specified /tmp will be used. - - - - -profilePath - - -Specifies the location of profile specification files. - - - - -attset - - -Specifies the filename(s) of attribute set files for use in -searching. At least the Bib-1 set should be loaded (bib1.att). -The profilePath setting is used to look for the specified files. -See section - - - - -memMax - - -Specifies size of internal memory to use for the zebraidx program. The -amount is given in megabytes - default is 4 (4 MB). - - - - - - - - - -Locating Records - - -The default behaviour of the Zebra system is to reference the -records from their original location, i.e. where they were found when you -ran zebraidx. That is, when a client wishes to retrieve a record -following a search operation, the files are accessed from the place -where you originally put them - if you remove the files (without -running zebraidx again, the client will receive a diagnostic -message. - - - -If your input files are not permanent - for example if you retrieve -your records from an outside source, or if they were temporarily -mounted on a CD-ROM drive, -you may want Zebra to make an internal copy of them. To do this, -you specify 1 (true) in the storeData setting. When -the Z39.50 server retrieves the records they will be read from the -internal file structures of the system. - - - - - -Indexing with no Record IDs (Simple Indexing) - - -If you have a set of records that are not expected to change over time -you may can build your database without record IDs. -This indexing method uses less space than the other methods and -is simple to use. - - - -To use this method, you simply omit the recordId entry -for the group of files that you index. To add a set of records you use -zebraidx with the update command. The -update command will always add all of the records that it -encounters to the index - whether they have already been indexed or -not. If the set of indexed files change, you should delete all of the -index files, and build a new index from scratch. - - - -Consider a system in which you have a group of text files called -simple. That group of records should belong to a Z39.50 database -called textbase. The following zebra.cfg file will suffice: - - - - - -profilePath: /usr/local/yaz -attset: bib1.att -simple.recordType: text -simple.database: textbase - - - - - -Since the existing records in an index can not be addressed by their -IDs, it is impossible to delete or modify records when using this method. - - - - - -Indexing with File Record IDs - - -If you have a set of files that regularly change over time: Old files -are deleted, new ones are added, or existing files are modified, you -can benefit from using the file ID indexing methodology. Examples -of this type of database might include an index of WWW resources, or a -USENET news spool area. Briefly speaking, the file key methodology -uses the directory paths of the individual records as a unique -identifier for each record. To perform indexing of a directory with -file keys, again, you specify the top-level directory after the -update command. The command will recursively traverse the -directories and compare each one with whatever have been indexed before in -that same directory. If a file is new (not in the previous version of -the directory) it is inserted into the registers; if a file was -already indexed and it has been modified since the last update, -the index is also modified; if a file has been removed since the last -visit, it is deleted from the index. - - - -The resulting system is easy to administrate. To delete a record you -simply have to delete the corresponding file (say, with the rm -command). And to add records you create new files (or directories with -files). For your changes to take effect in the register you must run -zebraidx update with the same directory root again. This mode -of operation requires more disk space than simpler indexing methods, -but it makes it easier for you to keep the index in sync with a -frequently changing set of data. If you combine this system with the -safe update facility (see below), you never have to take your -server offline for maintenance or register updating purposes. - - - -To enable indexing with pathname IDs, you must specify file as -the value of recordId in the configuration file. In addition, -you should set storeKeys to 1, since the Zebra -indexer must save additional information about the contents of each record -in order to modify the indices correctly at a later time. - - - -For example, to update records of group esdd located below -/data1/records/ you should type: - - -$ zebraidx -g esdd update /data1/records - - - - - -The corresponding configuration file includes: - - -esdd.recordId: file -esdd.recordType: grs.sgml -esdd.storeKeys: 1 - - - - - -Important note: You cannot start out with a group of records with simple -indexing (no record IDs as in the previous section) and then later -enable file record Ids. Zebra must know from the first time that you -index the group that -the files should be indexed with file record IDs. - - - -You cannot explicitly delete records when using this method (using the -delete command to zebraidx. Instead -you have to delete the files from the file system (or move them to a -different location) -and then run zebraidx with the update command. - - - - - -Indexing with General Record IDs - - -When using this method you construct an (almost) arbritrary, internal -record key based on the contents of the record itself and other system -information. If you have a group of records that explicitly associates -an ID with each record, this method is convenient. For example, the -record format may contain a title or a ID-number - unique within the group. -In either case you specify the Z39.50 attribute set and use-attribute -location in which this information is stored, and the system looks at -that field to determine the identity of the record. - - - -As before, the record ID is defined by the recordId setting -in the configuration file. The value of the record ID specification -consists of one or more tokens separated by whitespace. The resulting -ID is -represented in the index by concatenating the tokens and separating them by -ASCII value (1). - - - -There are three kinds of tokens: - - - -Internal record info - - -The token refers to a key that is -extracted from the record. The syntax of this token is -( set , use ), where set is the -attribute set name use is the name or value of the attribute. - - - - -System variable - - -The system variables are preceded by - - -$ - - and immediately followed by the system variable name, which -may one of - - - -group - - -Group name. - - - - -database - - -Current database specified. - - - - -type - - -Record type. - - - - - - - - -Constant string - - -A string used as part of the ID — surrounded -by single- or double quotes. - - - - - - - -For instance, the sample GILS records that come with the Zebra -distribution contain a unique ID in the data tagged Control-Identifier. -The data is mapped to the Bib-1 use attribute Identifier-standard -(code 1007). To use this field as a record id, specify -(bib1,Identifier-standard) as the value of the -recordId in the configuration file. -If you have other record types that uses the same field for a -different purpose, you might add the record type -(or group or database name) to the record id of the gils -records as well, to prevent matches with other types of records. -In this case the recordId might be set like this: - - -gils.recordId: $type (bib1,Identifier-standard) - - - - - -(see section -for details of how the mapping between elements of your records and -searchable attributes is established). - - - -As for the file record ID case described in the previous section, -updating your system is simply a matter of running zebraidx -with the update command. However, the update with general -keys is considerably slower than with file record IDs, since all files -visited must be (re)read to discover their IDs. - - - -As you might expect, when using the general record IDs -method, you can only add or modify existing records with the update -command. If you wish to delete records, you must use the, -delete command, with a directory as a parameter. -This will remove all records that match the files below that root -directory. - - + Administrating Zebra + + + Unlike many simpler retrieval systems, Zebra supports safe, incremental + updates to an existing index. + + + + Normally, when Zebra modifies the index it reads a number of records + that you specify. + Depending on your specifications and on the contents of each record + one the following events take place for each record: + + + + Insert + + + The record is indexed as if it never occurred before. + Either the Zebra system doesn't know how to identify the record or + Zebra can identify the record but didn't find it to be already indexed. + + + + + Modify + + + The record has already been indexed. In this case + either the contents of the record or the location (file) of the record + indicates that it has been indexed before. + + + + + Delete + + + The record is deleted from the index. As in the + update-case it must be able to identify the record. + + + + + + + + Please note that in both the modify- and delete- case the Zebra + indexer must be able to generate a unique key that identifies the record in + question (more on this below). + + + + To administrate the Zebra retrieval system, you run the + zebraidx program. + This program supports a number of options which are preceded by a dash, + and a few commands (not preceded by dash). + + + + Both the Zebra administrative tool and the Z39.50 server share a + set of index files and a global configuration file. The + name of the configuration file defaults to zebra.cfg. + The configuration file includes specifications on how to index + various kinds of records and where the other configuration files + are located. zebrasrv and zebraidx + must be run in the directory where the + configuration file lives unless you indicate the location of the + configuration file by option -c. + + + + Record Types + + + Indexing is a per-record process, in which either insert/modify/delete + will occur. Before a record is indexed search keys are extracted from + whatever might be the layout the original record (sgml,html,text, etc..). + The Zebra system currently supports two fundamantal types of records: + structured and simple text. + To specify a particular extraction process, use either the + command line option -t or specify a + recordType setting in the configuration file. + + + + + + The Zebra Configuration File + + + The Zebra configuration file, read by zebraidx and + zebrasrv defaults to zebra.cfg + unless specified by -c option. + + + + You can edit the configuration file with a normal text editor. + parameter names and values are seperated by colons in the file. Lines + starting with a hash sign (#) are + treated as comments. + + + + If you manage different sets of records that share common + characteristics, you can organize the configuration settings for each + type into "groups". + When zebraidx is run and you wish to address a + given group you specify the group name with the -g + option. + In this case settings that have the group name as their prefix + will be used by zebraidx. + If no -g option is specified, the settings + without prefix are used. + + + + In the configuration file, the group name is placed before the option + name itself, separated by a dot (.). For instance, to set the record type + for group public to grs.sgml + (the SGML-like format for structured records) you would write: + + + + + public.recordType: grs.sgml + + + + + To set the default value of the record type to text + write: + + + + + recordType: text + + + + + The available configuration settings are summarized below. They will be + explained further in the following sections. + + + + + + + + group + .recordType[.name] + + + + Specifies how records with the file extension + name should be handled by the indexer. + This option may also be specified as a command line option + (-t). Note that if you do not specify a + name, the setting applies to all files. + In general, the record type specifier consists of the elements (each + element separated by dot), fundamental-type, + file-read-type and arguments. Currently, two + fundamental types exist, text and + grs. + + + + + group.recordId + + + Specifies how the records are to be identified when updated. See + section . + + + + + group.database + + + Specifies the Z39.50 database name. + + + + + group.storeKeys + + + Specifies whether key information should be saved for a given + group of records. If you plan to update/delete this type of + records later this should be specified as 1; otherwise it + should be 0 (default), to save register space. See section + . + + + + + group.storeData + + + Specifies whether the records should be stored internally + in the Zebra system files. + If you want to maintain the raw records yourself, + this option should be false (0). + If you want Zebra to take care of the records for you, it + should be true(1). + + + + + register + + + Specifies the location of the various register files that Zebra uses + to represent your databases. See section + . + + + + + shadow + + + Enables the safe update facility of Zebra, and + tells the system where to place the required, temporary files. + See section + . + + + + + lockDir + + + Directory in which various lock files are stored. + + + + + keyTmpDir + + + Directory in which temporary files used during zebraidx' update + phase are stored. + + + + + setTmpDir + + + Specifies the directory that the server uses for temporary result sets. + If not specified /tmp will be used. + + + + + profilePath + + + Specifies the location of profile specification files. + + + + + attset + + + Specifies the filename(s) of attribute set files for use in + searching. At least the Bib-1 set should be loaded + (bib1.att). + The profilePath setting is used to look for + the specified files. + See section + + + + + memMax + + + Specifies size of internal memory to use for the zebraidx program. The + amount is given in megabytes - default is 4 (4 MB). + + + + + + + + + + Locating Records + + + The default behaviour of the Zebra system is to reference the + records from their original location, i.e. where they were found when you + ran zebraidx. + That is, when a client wishes to retrieve a record + following a search operation, the files are accessed from the place + where you originally put them - if you remove the files (without + running zebraidx again, the client + will receive a diagnostic message. + + + + If your input files are not permanent - for example if you retrieve + your records from an outside source, or if they were temporarily + mounted on a CD-ROM drive, + you may want Zebra to make an internal copy of them. To do this, + you specify 1 (true) in the storeData setting. When + the Z39.50 server retrieves the records they will be read from the + internal file structures of the system. + + + + + + Indexing with no Record IDs (Simple Indexing) + + + If you have a set of records that are not expected to change over time + you may can build your database without record IDs. + This indexing method uses less space than the other methods and + is simple to use. + + + + To use this method, you simply omit the recordId entry + for the group of files that you index. To add a set of records you use + zebraidx with the update command. The + update command will always add all of the records that it + encounters to the index - whether they have already been indexed or + not. If the set of indexed files change, you should delete all of the + index files, and build a new index from scratch. + + + + Consider a system in which you have a group of text files called + simple. + That group of records should belong to a Z39.50 database called + textbase. + The following zebra.cfg file will suffice: + + + + + profilePath: /usr/local/yaz + attset: bib1.att + simple.recordType: text + simple.database: textbase + + + + + + Since the existing records in an index can not be addressed by their + IDs, it is impossible to delete or modify records when using this method. + + + + + + Indexing with File Record IDs + + + If you have a set of files that regularly change over time: Old files + are deleted, new ones are added, or existing files are modified, you + can benefit from using the file ID + indexing methodology. + Examples of this type of database might include an index of WWW + resources, or a USENET news spool area. + Briefly speaking, the file key methodology uses the directory paths + of the individual records as a unique identifier for each record. + To perform indexing of a directory with file keys, again, you specify + the top-level directory after the update command. + The command will recursively traverse the directories and compare + each one with whatever have been indexed before in that same directory. + If a file is new (not in the previous version of the directory) it + is inserted into the registers; if a file was already indexed and + it has been modified since the last update, the index is also + modified; if a file has been removed since the last + visit, it is deleted from the index. + + + + The resulting system is easy to administrate. To delete a record you + simply have to delete the corresponding file (say, with the + rm command). And to add records you create new + files (or directories with files). For your changes to take effect + in the register you must run zebraidx update with + the same directory root again. This mode of operation requires more + disk space than simpler indexing methods, but it makes it easier for + you to keep the index in sync with a frequently changing set of data. + If you combine this system with the safe update + facility (see below), you never have to take your server offline for + maintenance or register updating purposes. + + + + To enable indexing with pathname IDs, you must specify + file as the value of recordId + in the configuration file. In addition, you should set + storeKeys to 1, since the Zebra + indexer must save additional information about the contents of each record + in order to modify the indices correctly at a later time. + + + + For example, to update records of group esdd + located below + /data1/records/ you should type: + + $ zebraidx -g esdd update /data1/records + + + + + The corresponding configuration file includes: + + esdd.recordId: file + esdd.recordType: grs.sgml + esdd.storeKeys: 1 + + + + + You cannot start out with a group of records with simple + indexing (no record IDs as in the previous section) and then later + enable file record Ids. Zebra must know from the first time that you + index the group that + the files should be indexed with file record IDs. + + + + + You cannot explicitly delete records when using this method (using the + delete command to zebraidx. Instead + you have to delete the files from the file system (or move them to a + different location) + and then run zebraidx with the + update command. + + + + Indexing with General Record IDs + + + When using this method you construct an (almost) arbritrary, internal + record key based on the contents of the record itself and other system + information. If you have a group of records that explicitly associates + an ID with each record, this method is convenient. For example, the + record format may contain a title or a ID-number - unique within the group. + In either case you specify the Z39.50 attribute set and use-attribute + location in which this information is stored, and the system looks at + that field to determine the identity of the record. + + + + As before, the record ID is defined by the recordId + setting in the configuration file. The value of the record ID specification + consists of one or more tokens separated by whitespace. The resulting + ID is represented in the index by concatenating the tokens and + separating them by ASCII value (1). + + + + There are three kinds of tokens: + + + + Internal record info + + + The token refers to a key that is + extracted from the record. The syntax of this token is + ( set , + use ), + where set is the + attribute set name use is the + name or value of the attribute. + + + + + System variable + + + The system variables are preceded by + + + $ + + and immediately followed by the system variable name, which + may one of + + + + group + + + Group name. + + + + + database + + + Current database specified. + + + + + type + + + Record type. + + + + + + + + + Constant string + + + A string used as part of the ID — surrounded + by single- or double quotes. + + + + + + + + For instance, the sample GILS records that come with the Zebra + distribution contain a unique ID in the data tagged Control-Identifier. + The data is mapped to the Bib-1 use attribute Identifier-standard + (code 1007). To use this field as a record id, specify + (bib1,Identifier-standard) as the value of the + recordId in the configuration file. + If you have other record types that uses the same field for a + different purpose, you might add the record type + (or group or database name) to the record id of the gils + records as well, to prevent matches with other types of records. + In this case the recordId might be set like this: + + + gils.recordId: $type (bib1,Identifier-standard) + + + + + + (see section + for details of how the mapping between elements of your records and + searchable attributes is established). + + + + As for the file record ID case described in the previous section, + updating your system is simply a matter of running + zebraidx + with the update command. However, the update with general + keys is considerably slower than with file record IDs, since all files + visited must be (re)read to discover their IDs. + + + + As you might expect, when using the general record IDs + method, you can only add or modify existing records with the + update command. + If you wish to delete records, you must use the, + delete command, with a directory as a parameter. + This will remove all records that match the files below that root + directory. + + + + + + Register Location + + + Normally, the index files that form dictionaries, inverted + files, record info, etc., are stored in the directory where you run + zebraidx. If you wish to store these, possibly large, + files somewhere else, you must add the register + entry to the zebra.cfg file. + Furthermore, the Zebra system allows its file + structures to span multiple file systems, which is useful for + managing very large databases. + + + + The value of the register setting is a sequence + of tokens. Each token takes the form: + + + dir:size. + + + The dir specifies a directory in which index files + will be stored and the size specifies the maximum + size of all files in that directory. The Zebra indexer system fills + each directory in the order specified and use the next specified + directories as needed. + The size is an integer followed by a qualifier + code, M for megabytes, + k for kilobytes. + + + + For instance, if you have allocated two disks for your register, and + the first disk is mounted + on /d1 and has 200 Mb of free space and the + second, mounted on /d2 has 300 Mb, you could + put this entry in your configuration file: + + + register: /d1:200M /d2:300M + + + + + + Note that Zebra does not verify that the amount of space specified is + actually available on the directory (file system) specified - it is + your responsibility to ensure that enough space is available, and that + other applications do not attempt to use the free space. In a large + production system, it is recommended that you allocate one or more + filesystem exclusively to the Zebra register files. + + + + + + Safe Updating - Using Shadow Registers + + + Description + + + The Zebra server supports updating of the index + structures. That is, you can add, modify, or remove records from + databases managed by Zebra without rebuilding the entire index. + Since this process involves modifying structured files with various + references between blocks of data in the files, the update process + is inherently sensitive to system crashes, or to process interruptions: + Anything but a successfully completed update process will leave the + register files in an unknown state, and you will essentially have no + recourse but to re-index everything, or to restore the register files + from a backup medium. + Further, while the update process is active, users cannot be + allowed to access the system, as the contents of the register files + may change unpredictably. + + + + You can solve these problems by enabling the shadow register system in + Zebra. + During the updating procedure, zebraidx will temporarily + write changes to the involved files in a set of "shadow + files", without modifying the files that are accessed by the + active server processes. If the update procedure is interrupted by a + system crash or a signal, you simply repeat the procedure - the + register files have not been changed or damaged, and the partially + written shadow files are automatically deleted before the new updating + procedure commences. + + + + At the end of the updating procedure (or in a separate operation, if + you so desire), the system enters a "commit mode". First, + any active server processes are forced to access those blocks that + have been changed from the shadow files rather than from the main + register files; the unmodified blocks are still accessed at their + normal location (the shadow files are not a complete copy of the + register files - they only contain those parts that have actually been + modified). If the commit process is interrupted at any point during the + commit process, the server processes will continue to access the + shadow files until you can repeat the commit procedure and complete + the writing of data to the main register files. You can perform + multiple update operations to the registers before you commit the + changes to the system files, or you can execute the commit operation + at the end of each update operation. When the commit phase has + completed successfully, any running server processes are instructed to + switch their operations to the new, operational register, and the + temporary shadow files are deleted. + + + + + + How to Use Shadow Register Files + + + The first step is to allocate space on your system for the shadow + files. + You do this by adding a shadow entry to the + zebra.cfg file. + The syntax of the shadow entry is exactly the + same as for the register entry + (see section ). + The location of the shadow area should be + different from the location of the main register + area (if you have specified one - remember that if you provide no + register setting, the default register area is the + working directory of the server and indexing processes). + + + + The following excerpt from a zebra.cfg file shows + one example of a setup that configures both the main register + location and the shadow file area. + Note that two directories or partitions have been set aside + for the shadow file area. You can specify any number of directories + for each of the file areas, but remember that there should be no + overlaps between the directories used for the main registers and the + shadow files, respectively. + + + + + register: /d1:500M + + shadow: /scratch1:100M /scratch2:200M + + + + + + When shadow files are enabled, an extra command is available at the + zebraidx command line. + In order to make changes to the system take effect for the + users, you'll have to submit a "commit" command after a + (sequence of) update operation(s). + You can ask the indexer to commit the changes immediately + after the update operation: + + + + + + $ zebraidx update /d1/records update /d2/more-records commit + + + + + + Or you can execute multiple updates before committing the changes: + + + + + + $ zebraidx -g books update /d1/records update /d2/more-records + $ zebraidx -g fun update /d3/fun-records + $ zebraidx commit + + + + + + If one of the update operations above had been interrupted, the commit + operation on the last line would fail: zebraidx + will not let you commit changes that would destroy the running register. + You'll have to rerun all of the update operations since your last + commit operation, before you can commit the new changes. + + + + Similarly, if the commit operation fails, zebraidx + will not let you start a new update operation before you have + successfully repeated the commit operation. + The server processes will keep accessing the shadow files rather + than the (possibly damaged) blocks of the main register files + until the commit operation has successfully completed. + + + + You should be aware that update operations may take slightly longer + when the shadow register system is enabled, since more file access + operations are involved. Further, while the disk space required for + the shadow register data is modest for a small update operation, you + may prefer to disable the system if you are adding a very large number + of records to an already very large database (we use the terms + large and modest + very loosely here, since every application will have a + different perception of size). + To update the system without the use of the the shadow files, + simply run zebraidx with the -n + option (note that you do not have to execute the + commit command of zebraidx + when you temporarily disable the use of the shadow registers in + this fashion. + Note also that, just as when the shadow registers are not enabled, + server processes will be barred from accessing the main register + while the update procedure takes place. + + + + + + + - -Register Location - - -Normally, the index files that form dictionaries, inverted -files, record info, etc., are stored in the directory where you run -zebraidx. If you wish to store these, possibly large, files -somewhere else, you must add the register entry to the -zebra.cfg file. Furthermore, the Zebra system allows its file -structures to -span multiple file systems, which is useful for managing very large -databases. - - - -The value of the register setting is a sequence of tokens. -Each token takes the form: - - -dir:size. - - -The dir specifies a directory in which index files will be -stored and the size specifies the maximum size of all -files in that directory. The Zebra indexer system fills each directory -in the order specified and use the next specified directories as needed. -The size is an integer followed by a qualifier -code, M for megabytes, k for kilobytes. - + + Running the Maintenance Interface (zebraidx) + + + The following is a complete reference to the command line interface to + the zebraidx application. + + + + Syntax + + + $ zebraidx [options] command [directory] ... + + + Options: + + + + -t type + + + Update all files as type. Currently, the + types supported are text and + grs.subtype. + If no subtype is provided for the GRS + (General Record Structure) type, the canonical input format + is assumed (see section ). + Generally, it is probably advisable to specify the record types + in the zebra.cfg file (see section + ), to avoid confusion at + subsequent updates. + + + + + -c config-file + + + Read the configuration file + config-file instead of + zebra.cfg. + + + + + -g group + + + Update the files according to the group + settings for group (see section + ). + + + + + -d database + + + The records located should be associated with the database name + database for access through the Z39.50 server. + + + + + -m mbytes + + + Use mbytes of megabytes before flushing + keys to background storage. This setting affects performance when + updating large databases. + + + + + -n + + + Disable the use of shadow registers for this operation + (see section ). + + + + + -s + + + Show analysis of the indexing process. The maintenance + program works in a read-only mode and doesn't change the state + of the index. This options is very useful when you wish to test a + new profile. + + + + + -V + + + Show Zebra version. + + + + + -v level + + + Set the log level to level. + level should be one of + none, debug, and + all. + + + + + + + + Commands + + + + update directory + + + Update the register with the files contained in + directory. + If no directory is provided, a list of files is read from + stdin. + See section . + + + + + delete directory + + + Remove the records corresponding to the files found under + directory from the register. + + + + + commit + + + Write the changes resulting from the last update + commands to the register. This command is only available if the use of + shadow register files is enabled (see section + ). + + + + + - -For instance, if you have allocated two disks for your register, and -the first disk is mounted -on /d1 and has 200 Mb of free space and the -second, mounted on /d2 has 300 Mb, you could -put this entry in your configuration file: + - -register: /d1:200M /d2:300M - + + The Z39.50 Server + + + Running the Z39.50 Server (zebrasrv) + + + Syntax + + + zebrasrv [options] [listener-address ...] + + + + + + Options + + + + -a APDU file + + + Specify a file for dumping PDUs (for diagnostic purposes). + The special name "-" sends output to stderr. + + + + + -c config-file + + + Read configuration information from + config-file. + The default configuration is ./zebra.cfg. + + + + + -S + + + Don't fork on connection requests. This can be useful for + symbolic-level debugging. The server can only accept a single + connection in this mode. + + + + + -s + + + Use the SR protocol. + + + + + -z + + + Use the Z39.50 protocol (default). These two options complement + eachother. You can use both multiple times on the same command + line, between listener-specifications (see below). This way, you + can set up the server to listen for connections in both protocols + concurrently, on different local ports. + + + + + -l logfile + + + Specify an output file for the diagnostic messages. + The default is to write this information to stderr. + + + + + -v log-level + + + The log level. Use a comma-separated list of members of the set + {fatal,debug,warn,log,all,none}. + + + + + -u username + + + Set user ID. Sets the real UID of the server process to that of the + given username. + It's useful if you aren't comfortable with having the + server run as root, but you need to start it as such to bind a + privileged port. + + + + + -w working-directory + + + Change working directory. + + + + + -i + + + Run under the Internet superserver, inetd. + Make sure you use the logfile option -l in + conjunction with this mode and specify the -l + option before any other options. + + + + + -t timeout + + + Set the idle session timeout (default 60 minutes). + + + + + -k kilobytes + + + Set the (approximate) maximum size of + present response messages. Default is 1024 Kb (1 Mb). + + + + + + + + A listener-address consists of a transport + mode followed by a colon (:) followed by a listener address. + The transport mode is either ssl or + tcp. + + + + For TCP, an address has the form + + + + + + hostname | IP-number [: portnumber] + + + + + + The port number defaults to 210 (standard Z39.50 port). + + + + Examples + + + + + + tcp:dranet.dra.com + + ssl:secure.lib.com:3000 + + + + + + In both cases, the special hostname "@" is mapped to + the address INADDR_ANY, which causes the server to listen on any local + interface. To start the server listening on the registered port for + Z39.50, and to drop root privileges once the ports are bound, execute + the server like this (from a root shell): + + + + + + zebrasrv -u daemon tcp:@ + + + + + + You can replace daemon with another user, eg. + your own account, or a dedicated IR server account. + + + + The default behavior for zebrasrv is to establish + a single TCP/IP listener, for the Z39.50 protocol, on port 9999. + + + + + + Z39.50 Protocol Support and Behavior + + + Initialization + + + During initialization, the server will negotiate to version 3 of the + Z39.50 protocol, and the option bits for Search, Present, Scan, + NamedResultSets, and concurrentOperations will be set, if requested by + the client. The maximum PDU size is negotiated down to a maximum of + 1Mb by default. + + + + + + Search + + + The supported query type are 1 and 101. All operators are currently + supported with the restriction that only proximity units of type "word" + are supported for the proximity operator. + Queries can be arbitrarily complex. + Named result sets are supported, and result sets can be used as operands + without limitations. + Searches may span multiple databases. + + + + The server has full support for piggy-backed present requests (see + also the following section). + + + + Use attributes are interpreted according to the + attribute sets which have been loaded in the + zebra.cfg file, and are matched against specific + fields as specified in the .abs file which + describes the profile of the records which have been loaded. + If no Use attribute is provided, a default of Bib-1 Any is assumed. + + + + If a Structure attribute of + Phrase is used in conjunction with a + Completeness attribute of + Complete (Sub)field, the term is matched + against the contents of the phrase (long word) register, if one + exists for the given Use attribute. + A phrase register is created for those fields in the + .abs file that contains a + p-specifier. + + + + If Structure=Phrase is + used in conjunction with Incomplete Field - the + default value for Completeness, the + search is directed against the normal word registers, but if the term + contains multiple words, the term will only match if all of the words + are found immediately adjacent, and in the given order. + The word search is performed on those fields that are indexed as + type w in the .abs file. + + + + If the Structure attribute is + Word List, + Free-form Text, or + Document Text, the term is treated as a + natural-language, relevance-ranked query. + This search type uses the word register, i.e. those fields + that are indexed as type w in the + .abs file. + + + + If the Structure attribute is + Numeric String the term is treated as an integer. + The search is performed on those fields that are indexed + as type n in the .abs file. + + + + If the Structure attribute is + URx the term is treated as a URX (URL) entity. + The search is performed on those fields that are indexed as type + u in the .abs file. + + + + If the Structure attribute is + Local Number the term is treated as + native Zebra Record Identifier. + + + + If the Relation attribute is + Equals (default), the term is matched + in a normal fashion (modulo truncation and processing of + individual words, if required). + If Relation is Less Than, + Less Than or Equal, + Greater than, or Greater than or + Equal, the term is assumed to be numerical, and a + standard regular expression is constructed to match the given + expression. + If Relation is Relevance, + the standard natural-language query processor is invoked. + + + + For the Truncation attribute, + No Truncation is the default. + Left Truncation is not supported. + Process # is supported, as is + Regxp-1. + Regxp-2 enables the fault-tolerant (fuzzy) + search. As a default, a single error (deletion, insertion, + replacement) is accepted when terms are matched against the register + contents. + + + + Regular expressions + + + Each term in a query is interpreted as a regular expression if + the truncation value is either Regxp-1 (102) + or Regxp-2 (103). + Both query types follow the same syntax with the operands: + + + + x + + + Matches the character x. + + + + + . + + + Matches any character. + + + + + [..] + + + Matches the set of characters specified; + such as [abc] or [a-c]. + + + + + and the operators: + + + + x* + + + Matches x zero or more times. Priority: high. + + + + + x+ + + + Matches x one or more times. Priority: high. + + + + + x? + + + Matches x once or twice. Priority: high. + + + + + xy + + + Matches x, then y. + Priority: medium. + + + + + x|y + + + Matches either x or y. + Priority: low. + + + + + The order of evaluation may be changed by using parentheses. + + + + If the first character of the Regxp-2 query + is a plus character (+) it marks the + beginning of a section with non-standard specifiers. + The next plus character marks the end of the section. + Currently Zebra only supports one specifier, the error tolerance, + which consists one digit. + + + + Since the plus operator is normally a suffix operator the addition to + the query syntax doesn't violate the syntax for standard regular + expressions. + + + + + + Query examples + + + Phrase search for information retrieval in + the title-register: + + @attr 1=4 "information retrieval" + + + + + Ranked search for the same thing: + + @attr 1=4 @attr 2=102 "Information retrieval" + + + + + Phrase search with a regular expression: + + @attr 1=4 @attr 5=102 "informat.* retrieval" + + + + + Ranked search with a regular expression: + + @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval" + + + + + In the GILS schema (gils.abs), the + west-bounding-coordinate is indexed as type n, + and is therefore searched by specifying + structure=Numeric String. + To match all those records with west-bounding-coordinate greater + than -114 we use the following query: + + @attr 4=109 @attr 2=5 @attr gils 1=2038 -114 + + + + + + + Present + + The present facility is supported in a standard fashion. The requested + record syntax is matched against the ones supported by the profile of + each record retrieved. If no record syntax is given, SUTRS is the + default. The requested element set name, again, is matched against any + provided by the relevant record profiles. + + + + Scan + + The attribute combinations provided with the termListAndStartPoint are + processed in the same way as operands in a query (see above). + Currently, only the term and the globalOccurrences are returned with + the termInfo structure. + + + + Sort + + + Z39.50 specifies three diffent types of sort criterias. + Of these Zebra supports the attribute specification type in which + case the use attribute specifies the "Sort register". + Sort registers are created for those fields that are of type "sort" in + the default.idx file. + The corresponding character mapping file in default.idx specifies the + ordinal of each character used in the actual sort. + + + + Z39.50 allows the client to specify sorting on one or more input + result sets and one output result set. + Zebra supports sorting on one result set only which may or may not + be the same as the output result set. + + + + Close + + If a Close PDU is received, the server will respond with a Close PDU + with reason=FINISHED, no matter which protocol version was negotiated + during initialization. If the protocol version is 3 or more, the + server will generate a Close PDU under certain circumstances, + including a session timeout (60 minutes by default), and certain kinds of + protocol errors. Once a Close PDU has been sent, the protocol + association is considered broken, and the transport connection will be + closed immediately upon receipt of further data, or following a short + timeout. + + + + - + + The Record Model + + + The Zebra system is designed to support a wide range of data management + applications. The system can be configured to handle virtually any + kind of structured data. Each record in the system is associated with + a record schema which lends context to the data + elements of the record. + Any number of record schema can coexist in the system. + Although it may be wise to use only a single schema within + one database, the system poses no such restrictions. + + + + The record model described in this chapter applies to the fundamental, + structured + record type grs as introduced in + section . + + + + Records pass through three different states during processing in the + system. + + + + + + + + + When records are accessed by the system, they are represented + in their local, or native format. This might be SGML or HTML files, + News or Mail archives, MARC records. If the system doesn't already + know how to read the type of data you need to store, you can set up an + input filter by preparing conversion rules based on regular + expressions and possibly augmented by a flexible scripting language + (Tcl). + The input filter produces as output an internal representation: + + + + + + + When records are processed by the system, they are represented + in a tree-structure, constructed by tagged data elements hanging off a + root node. The tagged elements may contain data or yet more tagged + elements in a recursive structure. The system performs various + actions on this tree structure (indexing, element selection, schema + mapping, etc.), + + + + + + + Before transmitting records to the client, they are first + converted from the internal structure to a form suitable for exchange + over the network - according to the Z39.50 standard. + + + + + + + + + Local Representation + + + As mentioned earlier, Zebra places few restrictions on the type of + data that you can index and manage. Generally, whatever the form of + the data, it is parsed by an input filter specific to that format, and + turned into an internal structure that Zebra knows how to handle. This + process takes place whenever the record is accessed - for indexing and + retrieval. + + + + The RecordType parameter in the zebra.cfg file, or + the -t option to the indexer tells Zebra how to + process input records. + Two basic types of processing are available - raw text and structured + data. Raw text is just that, and it is selected by providing the + argument text to Zebra. Structured records are + all handled internally using the basic mechanisms described in the + subsequent sections. + Zebra can read structured records in many different formats. + How this is done is governed by additional parameters after the + "grs" keyboard, separated by "." characters. + + + + Three basic subtypes to the grs type are + currently available: + + + + + + grs.sgml + + + This is the canonical input format — + described below. It is a simple SGML-like syntax. + + + + + grs.regx.filter + + + This enables a user-supplied input + filter. The mechanisms of these filters are described below. + + + + + grs.marc.abstract syntax + + + This allows Zebra to read + records in the ISO2709 (MARC) encoding standard. In this case, the + last paramemeter abstract syntax names the + .abs file (see below) + which describes the specific MARC structure of the input record as + well as the indexing rules. + + + + + + + + Canonical Input Format + + + Although input data can take any form, it is sometimes useful to + describe the record processing capabilities of the system in terms of + a single, canonical input format that gives access to the full + spectrum of structure and flexibility in the system. In Zebra, this + canonical format is an "SGML-like" syntax. + + + + To use the canonical format specify grs.sgml as + the record type. + + + + Consider a record describing an information resource (such a record is + sometimes known as a locator record). + It might contain a field describing the distributor of the + information resource, which might in turn be partitioned into + various fields providing details about the distributor, like this: + + + + + + <Distributor> + <Name> USGS/WRD </Name> + <Organization> USGS/WRD </Organization> + <Street-Address> + U.S. GEOLOGICAL SURVEY, 505 MARQUETTE, NW + </Street-Address> + <City> ALBUQUERQUE </City> + <State> NM </State> + <Zip-Code> 87102 </Zip-Code> + <Country> USA </Country> + <Telephone> (505) 766-5560 </Telephone> + </Distributor> + + + + + + + The indentation used above is used to illustrate how Zebra + interprets the markup. The indentation, in itself, has no + significance to the parser for the canonical input format, which + discards superfluous whitespace. + + + + The keywords surrounded by <...> are + tags, while the sections of text + in between are the data elements. + A data element is characterized by its location in the tree + that is made up by the nested elements. + Each element is terminated by a closing tag - beginning + with </, and containing the same symbolic + tag-name as the corresponding opening tag. + The general closing tag - <>/ - + terminates the element started by the last opening tag. The + structuring of elements is significant. + The element Telephone, + for instance, may be indexed and presented to the client differently, + depending on whether it appears inside the + Distributor element, or some other, + structured data element such a Supplier element. + + + + Record Root + + + The first tag in a record describes the root node of the tree that + makes up the total record. In the canonical input format, the root tag + should contain the name of the schema that lends context to the + elements of the record (see section + ). + The following is a GILS record that + contains only a single element (strictly speaking, that makes it an + illegal GILS record, since the GILS profile includes several mandatory + elements - Zebra does not validate the contents of a record against + the Z39.50 profile, however - it merely attempts to match up elements + of a local representation with the given schema): + + + + + + <gils> + <title>Zen and the Art of Motorcycle Maintenance</title> + </gils> + + + + + + + + Variants + + + Zebra allows you to provide individual data elements in a number of + variant forms. Examples of variant forms are + textual data elements which might appear in different languages, and + images which may appear in different formats or layouts. + The variant system in Zebra is essentially a representation of + the variant mechanism of Z39.50-1995. + + + + The following is an example of a title element which occurs in two + different languages. + + + + + + <title> + <var lang lang "eng"> + Zen and the Art of Motorcycle Maintenance</> + <var lang lang "dan"> + Zen og Kunsten at Vedligeholde en Motorcykel</> + </title> + + + + + + The syntax of the variant element is + <var class type value>. + The available values for the class and + type fields are given by the variant set + that is associated with the current schema + (see section ). + + + + Variant elements are terminated by the general end-tag </>, by + the variant end-tag </var>, by the appearance of another variant + tag with the same class and + value settings, or by the + appearance of another, normal tag. In other words, the end-tags for + the variants used in the example above could have been saved. + + + + Variant elements can be nested. The element + + + + + + <title> + <var lang lang "eng"><var body iana "text/plain"> + Zen and the Art of Motorcycle Maintenance + </title> + - -Note that Zebra does not verify that the amount of space specified is -actually available on the directory (file system) specified - it is -your responsibility to ensure that enough space is available, and that -other applications do not attempt to use the free space. In a large production system, -it is recommended that you allocate one or more filesystem exclusively -to the Zebra register files. - + - + + Associates two variant components to the variant list for the title + element. + - -Safe Updating - Using Shadow Registers + + Given the nesting rules described above, we could write + - -Description + - -The Zebra server supports updating of the index structures. That is, -you can add, modify, or remove records from databases managed by Zebra -without rebuilding the entire index. Since this process involves -modifying structured files with various references between blocks of -data in the files, the update process is inherently sensitive to -system crashes, or to process interruptions: Anything but a -successfully completed update process will leave the register files in -an unknown state, and you will essentially have no recourse but to -re-index everything, or to restore the register files from a backup -medium. Further, while the update process is active, users cannot be -allowed to access the system, as the contents of the register files -may change unpredictably. - - - -You can solve these problems by enabling the shadow register system in -Zebra. During the updating procedure, zebraidx will temporarily -write changes to the involved files in a set of "shadow -files", without modifying the files that are accessed by the -active server processes. If the update procedure is interrupted by a -system crash or a signal, you simply repeat the procedure - the -register files have not been changed or damaged, and the partially -written shadow files are automatically deleted before the new updating -procedure commences. - - - -At the end of the updating procedure (or in a separate operation, if -you so desire), the system enters a "commit mode". First, -any active server processes are forced to access those blocks that -have been changed from the shadow files rather than from the main -register files; the unmodified blocks are still accessed at their -normal location (the shadow files are not a complete copy of the -register files - they only contain those parts that have actually been -modified). If the commit process is interrupted at any point during the -commit process, the server processes will continue to access the -shadow files until you can repeat the commit procedure and complete -the writing of data to the main register files. You can perform -multiple update operations to the registers before you commit the -changes to the system files, or you can execute the commit operation -at the end of each update operation. When the commit phase has -completed successfully, any running server processes are instructed to -switch their operations to the new, operational register, and the -temporary shadow files are deleted. - - - - - -How to Use Shadow Register Files - - -The first step is to allocate space on your system for the shadow -files. You do this by adding a shadow entry to the zebra.cfg -file. The syntax of the shadow entry is exactly the same as for -the register entry (see section ). The location of the shadow area should be -different from the location of the main register area (if you -have specified one - remember that if you provide no register -setting, the default register area is the -working directory of the server and indexing processes). - - - -The following excerpt from a zebra.cfg file shows one example of -a setup that configures both the main register location and the shadow -file area. Note that two directories or partitions have been set aside -for the shadow file area. You can specify any number of directories -for each of the file areas, but remember that there should be no -overlaps between the directories used for the main registers and the -shadow files, respectively. - - - - - -register: /d1:500M - -shadow: /scratch1:100M /scratch2:200M - - - - - -When shadow files are enabled, an extra command is available at the -zebraidx command line. In order to make changes to the system -take effect for the users, you'll have to submit a -"commit" command after a (sequence of) update -operation(s). You can ask the indexer to commit the changes -immediately after the update operation: - - - - - -$ zebraidx update /d1/records update /d2/more-records commit - - - - - -Or you can execute multiple updates before committing the changes: - - - - - -$ zebraidx -g books update /d1/records update /d2/more-records -$ zebraidx -g fun update /d3/fun-records -$ zebraidx commit - - - - - -If one of the update operations above had been interrupted, the commit -operation on the last line would fail: zebraidx will not let you -commit changes that would destroy the running register. You'll have to -rerun all of the update operations since your last commit operation, -before you can commit the new changes. - - - -Similarly, if the commit operation fails, zebraidx will not let -you start a new update operation before you have successfully repeated -the commit operation. The server processes will keep accessing the -shadow files rather than the (possibly damaged) blocks of the main -register files until the commit operation has successfully completed. - - - -You should be aware that update operations may take slightly longer -when the shadow register system is enabled, since more file access -operations are involved. Further, while the disk space required for -the shadow register data is modest for a small update operation, you -may prefer to disable the system if you are adding a very large number -of records to an already very large database (we use the terms -large and modest very loosely here, since every -application will have a different perception of size). To update the system -without the use of the the shadow files, simply run zebraidx with -the -n option (note that you do not have to execute the -commit command of zebraidx when you temporarily disable the -use of the shadow registers in this fashion. Note also that, just as -when the shadow registers are not enabled, server processes will be -barred from accessing the main register while the update procedure -takes place. - - - - - - - - - -Running the Maintenance Interface (zebraidx) - - -The following is a complete reference to the command line interface to -the zebraidx application. - - - -Syntax - - -$ zebraidx [options] command [directory] ... - - -Options - - - --t type - - -Update all files as type. Currently, the -types supported are text and grs.subtype. If no -subtype is provided for the GRS (General Record Structure) type, -the canonical input format is assumed (see section ). Generally, it -is probably advisable to specify the record types in the -zebra.cfg file -(see section ), to avoid -confusion at subsequent updates. - - - - --c config-file - - -Read the configuration file -config-file instead of zebra.cfg. - - - - --g group - - -Update the files according to the group -settings for group (see section -). - - - - --d database - - -The records located should be associated -with the database name database for access through the Z39.50 -server. - - - - --m mbytes - - -Use mbytes of megabytes before flushing -keys to background storage. This setting affects performance when -updating large databases. - - - - --n - - -Disable the use of shadow registers for this operation -(see section ). - - - - --s - - -Show analysis of the indexing process. The maintenance -program works in a read-only mode and doesn't change the state -of the index. This options is very useful when you wish to test a -new profile. - - - - --V - - -Show Zebra version. - - - - --v level - - -Set the log level to level. level -should be one of none, debug, and all. - - - - - - - -Commands - - - -Update directory - - -Update the register with the files -contained in directory. If no directory is provided, a list of -files is read from stdin. -See section . - - - - -Delete directory - - -Remove the records corresponding to -the files found under directory from the register. - - - - -Commit - - -Write the changes resulting from the last update -commands to the register. This command is only available if the use of -shadow register files is enabled (see section -). - - - - - - - - - -The Z39.50 Server - - -Running the Z39.50 Server (zebrasrv) - - -Syntax - - -zebrasrv [options] [listener-address ...] - - - - - -Options - - - --a APDU file - - -Specify a file for dumping PDUs (for diagnostic purposes). -The special name "-" sends output to stderr. - - - - --c config-file - - -Read configuration information from config-file. The default configuration is ./zebra.cfg. - - - - --S - - -Don't fork on connection requests. This can be useful for -symbolic-level debugging. The server can only accept a single -connection in this mode. - - - - --s - - -Use the SR protocol. - - - - --z - - -Use the Z39.50 protocol (default). These two options complement -eachother. You can use both multiple times on the same command -line, between listener-specifications (see below). This way, you -can set up the server to listen for connections in both protocols -concurrently, on different local ports. - - - - --l logfile - - -Specify an output file for the diagnostic -messages. The default is to write this information to stderr. - - - - --v log-level - - -The log level. Use a comma-separated list of members of the set -{fatal,debug,warn,log,all,none}. - - - - --u username - - -Set user ID. Sets the real UID of the server process to that of the -given username. It's useful if you aren't comfortable with having the -server run as root, but you need to start it as such to bind a -privileged port. - - - - --w working-directory - - -Change working directory. - - - - --i - - -Run under the Internet superserver, inetd. Make -sure you use the logfile option -l in conjunction with this -mode and specify the -l option before any other options. - - - - --t timeout - - -Set the idle session timeout (default 60 minutes). - - - - --k kilobytes - - -Set the (approximate) maximum size of -present response messages. Default is 1024 Kb (1 Mb). - - - - - - - -A listener-address consists of a transport mode followed by a -colon (:) followed by a listener address. The transport mode is -either osi or tcp. - - - -For TCP, an address has the form - - - - - -hostname | IP-number [: portnumber] - - - - - -The port number defaults to 210 (standard Z39.50 port). - - - -For OSI (only available if the server is compiled with XTI/mOSI -support enabled), the address form is - - - - - -[t-selector /] hostname | IP-number [: portnumber] - - - - - -The transport selector is given as a string of hex digits (with an even -number of digits). The default port number is 102 (RFC1006 port). - - - -Examples - - - - - -tcp:dranet.dra.com - -osi:0402/dbserver.osiworld.com:3000 - - - - - -In both cases, the special hostname "@" is mapped to -the address INADDR_ANY, which causes the server to listen on any local -interface. To start the server listening on the registered ports for -Z39.50 and SR over OSI/RFC1006, and to drop root privileges once the -ports are bound, execute the server like this (from a root shell): - - - - - -zebrasrv -u daemon tcp:@ -s osi:@ - - - - - -You can replace daemon with another user, eg. your own account, or -a dedicated IR server account. - - - -The default behavior for zebrasrv is to establish a single TCP/IP -listener, for the Z39.50 protocol, on port 9999. - - - - - -Z39.50 Protocol Support and Behavior - - -Initialization - - -During initialization, the server will negotiate to version 3 of the -Z39.50 protocol, and the option bits for Search, Present, Scan, -NamedResultSets, and concurrentOperations will be set, if requested by -the client. The maximum PDU size is negotiated down to a maximum of -1Mb by default. - - - - - -Search - - -The supported query type are 1 and 101. All operators are currently -supported with the restriction that only proximity units of type "word" are -supported for the proximity operator. -Queries can be arbitrarily complex. -Named result sets are supported, and result sets can be used as operands -without limitations. -Searches may span multiple databases. - - - -The server has full support for piggy-backed present requests (see -also the following section). - - - -Use attributes are interpreted according to the attribute sets which -have been loaded in the zebra.cfg file, and are matched against -specific fields as specified in the .abs file which describes the -profile of the records which have been loaded. If no Use -attribute is provided, a default of Bib-1 Any is assumed. - - - -If a Structure attribute of Phrase is used in conjunction with a -Completeness attribute of Complete (Sub)field, the term is -matched against the contents of the phrase (long word) register, if one -exists for the given Use attribute. -A phrase register is created for those fields in the .abs -file that contains a p-specifier. - - - -If Structure=Phrase is used in conjunction with -Incomplete Field - the default value for Completeness, the -search is directed against the normal word registers, but if the term -contains multiple words, the term will only match if all of the words -are found immediately adjacent, and in the given order. -The word search is performed on those fields that are indexed as -type w in the .abs file. - - - -If the Structure attribute is Word List, -Free-form Text, or Document Text, the term is treated as a -natural-language, relevance-ranked query. -This search type uses the word register, i.e. those fields -that are indexed as type w in the .abs file. - - - -If the Structure attribute is Numeric String the -term is treated as an integer. The search is performed on those -fields that are indexed as type n in the .abs file. - - - -If the Structure attribute is URx the -term is treated as a URX (URL) entity. The search is performed on those -fields that are indexed as type u in the .abs file. - - - -If the Structure attribute is Local Number the -term is treated as native Zebra Record Identifier. - - - -If the Relation attribute is Equals (default), the term is -matched in a normal fashion (modulo truncation and processing of -individual words, if required). If Relation is Less Than, -Less Than or Equal, Greater than, or Greater than or -Equal, the term is assumed to be numerical, and a standard regular -expression is constructed to match the given expression. If -Relation is Relevance, the standard natural-language query -processor is invoked. - - - -For the Truncation attribute, No Truncation is the default. -Left Truncation is not supported. Process # is supported, as -is Regxp-1. Regxp-2 enables the fault-tolerant (fuzzy) -search. As a default, a single error (deletion, insertion, -replacement) is accepted when terms are matched against the register -contents. - - - -Regular expressions - - -Each term in a query is interpreted as a regular expression if -the truncation value is either Regxp-1 (102) or Regxp-2 (103). -Both query types follow the same syntax with the operands: - - - -x - - -Matches the character x. - - - - -. - - -Matches any character. - - - - -[..] - - -Matches the set of characters specified; -such as [abc] or [a-c]. - - - - -and the operators: - - - -x* - - -Matches x zero or more times. Priority: high. - - - - -x+ - - -Matches x one or more times. Priority: high. - - - - -x? - - -Matches x once or twice. Priority: high. - - - - -xy - - -Matches x, then y. Priority: medium. - - - - -x|y - - -Matches either x or y. Priority: low. - - - - -The order of evaluation may be changed by using parentheses. - - - -If the first character of the Regxp-2 query is a plus character -(+) it marks the beginning of a section with non-standard -specifiers. The next plus character marks the end of the section. -Currently Zebra only supports one specifier, the error tolerance, -which consists one digit. - - - -Since the plus operator is normally a suffix operator the addition to -the query syntax doesn't violate the syntax for standard regular -expressions. - - - - - -Query examples - - -Phrase search for information retrieval in the title-register: - - - @attr 1=4 "information retrieval" - - - - - -Ranked search for the same thing: - - - @attr 1=4 @attr 2=102 "Information retrieval" - - - - - -Phrase search with a regular expression: - - - @attr 1=4 @attr 5=102 "informat.* retrieval" - - - - - -Ranked search with a regular expression: - - - @attr 1=4 @attr 5=102 @attr 2=102 "informat.* retrieval" - - - - - -In the GILS schema (gils.abs), the west-bounding-coordinate is -indexed as type n, and is therefore searched by specifying -structure=Numeric String. -To match all those records with west-bounding-coordinate greater -than -114 we use the following query: - - - @attr 4=109 @attr 2=5 @attr gils 1=2038 -114 - - - - - - - - - -Present - - -The present facility is supported in a standard fashion. The requested -record syntax is matched against the ones supported by the profile of -each record retrieved. If no record syntax is given, SUTRS is the -default. The requested element set name, again, is matched against any -provided by the relevant record profiles. - - - - - -Scan - - -The attribute combinations provided with the termListAndStartPoint are -processed in the same way as operands in a query (see above). -Currently, only the term and the globalOccurrences are returned with -the termInfo structure. - - - - - -Sort - - -Z39.50 specifies three diffent types of sort criterias. -Of these Zebra supports the attribute specification type in which -case the use attribute specifies the "Sort register". -Sort registers are created for those fields that are of type "sort" in -the default.idx file. -The corresponding character mapping file in default.idx specifies the -ordinal of each character used in the actual sort. - - - -Z39.50 allows the client to specify sorting on one or more input -result sets and one output result set. -Zebra supports sorting on one result set only which may or may not -be the same as the output result set. - - - - - -Close - - -If a Close PDU is received, the server will respond with a Close PDU -with reason=FINISHED, no matter which protocol version was negotiated -during initialization. If the protocol version is 3 or more, the -server will generate a Close PDU under certain circumstances, -including a session timeout (60 minutes by default), and certain kinds of -protocol errors. Once a Close PDU has been sent, the protocol -association is considered broken, and the transport connection will be -closed immediately upon receipt of further data, or following a short -timeout. - - - - - - - - - -The Record Model - - -The Zebra system is designed to support a wide range of data management -applications. The system can be configured to handle virtually any -kind of structured data. Each record in the system is associated with -a record schema which lends context to the data elements of the -record. Any number of record schema can coexist in the system. -Although it may be wise to use only a single schema within -one database, the system poses no such restrictions. - - - -The record model described in this chapter applies to the fundamental, -structured -record type grs as introduced in -section . - - - -Records pass through three different states during processing in the -system. - - - - - - - - -When records are accessed by the system, they are represented -in their local, or native format. This might be SGML or HTML files, -News or Mail archives, MARC records. If the system doesn't already -know how to read the type of data you need to store, you can set up an -input filter by preparing conversion rules based on regular -expressions and possibly augmented by a flexible scripting language (Tcl). The input filter -produces as output an internal representation: - - - - - - -When records are processed by the system, they are represented -in a tree-structure, constructed by tagged data elements hanging off a -root node. The tagged elements may contain data or yet more tagged -elements in a recursive structure. The system performs various -actions on this tree structure (indexing, element selection, schema -mapping, etc.), - - - - - - -Before transmitting records to the client, they are first -converted from the internal structure to a form suitable for exchange -over the network - according to the Z39.50 standard. - - - - - - - - -Local Representation - - -As mentioned earlier, Zebra places few restrictions on the type of -data that you can index and manage. Generally, whatever the form of -the data, it is parsed by an input filter specific to that format, and -turned into an internal structure that Zebra knows how to handle. This -process takes place whenever the record is accessed - for indexing and -retrieval. - - - -The RecordType parameter in the zebra.cfg file, or the -t -option to the indexer tells Zebra how to process input records. Two -basic types of processing are available - raw text and structured -data. Raw text is just that, and it is selected by providing the -argument text to Zebra. Structured records are all handled -internally using the basic mechanisms described in the subsequent -sections. Zebra can read structured records in many different formats. -How this is done is governed by additional parameters after the -"grs" keyboard, separated by "." characters. - - - -Three basic subtypes to the grs type are currently available: - - - - - - -grs.sgml - - -This is the canonical input format — -described below. It is a simple SGML-like syntax. - - - - -grs.regx.filter - - -This enables a user-supplied input -filter. The mechanisms of these filters are described below. - - - - -grs.marc.abstract syntax - - -This allows Zebra to read -records in the ISO2709 (MARC) encoding standard. In this case, the -last paramemeter abstract syntax names the .abs file (see below) -which describes the specific MARC structure of the input record as -well as the indexing rules. - - - - - - - -Canonical Input Format - - -Although input data can take any form, it is sometimes useful to -describe the record processing capabilities of the system in terms of -a single, canonical input format that gives access to the full -spectrum of structure and flexibility in the system. In Zebra, this -canonical format is an "SGML-like" syntax. - - - -To use the canonical format specify grs.sgml as the record -type, - - - -Consider a record describing an information resource (such a record is -sometimes known as a locator record). It might contain a field -describing the distributor of the information resource, which might in -turn be partitioned into various fields providing details about the -distributor, like this: - - - - - -<Distributor> - <Name> USGS/WRD </Name> - <Organization> USGS/WRD </Organization> - <Street-Address> - U.S. GEOLOGICAL SURVEY, 505 MARQUETTE, NW - </Street-Address> - <City> ALBUQUERQUE </City> - <State> NM </State> - <Zip-Code> 87102 </Zip-Code> - <Country> USA </Country> - <Telephone> (505) 766-5560 </Telephone> -</Distributor> - - - - - -NOTE: The indentation used above is used to illustrate how Zebra -interprets the markup. The indentation, in itself, has no -significance to the parser for the canonical input format, which -discards superfluous whitespace. - - - -The keywords surrounded by <...> are tags, while the -sections of text in between are the data elements. A data element -is characterized by its location in the tree that is made up by the -nested elements. Each element is terminated by a closing tag - -beginning with </, and containing the same symbolic tag-name as -the corresponding opening tag. The general closing tag - <>/ - -terminates the element started by the last opening tag. The -structuring of elements is significant. The element Telephone, -for instance, may be indexed and presented to the client differently, -depending on whether it appears inside the Distributor element, -or some other, structured data element such a Supplier element. - - - -Record Root - - -The first tag in a record describes the root node of the tree that -makes up the total record. In the canonical input format, the root tag -should contain the name of the schema that lends context to the -elements of the record (see section -). -The following is a GILS record that -contains only a single element (strictly speaking, that makes it an -illegal GILS record, since the GILS profile includes several mandatory -elements - Zebra does not validate the contents of a record against -the Z39.50 profile, however - it merely attempts to match up elements -of a local representation with the given schema): - - - - - -<gils> - <title>Zen and the Art of Motorcycle Maintenance</title> -</gils> - - - - - - - -Variants - - -Zebra allows you to provide individual data elements in a number of -variant forms. Examples of variant forms are textual data -elements which might appear in different languages, and images which -may appear in different formats or layouts. The variant system in -Zebra is -essentially a representation of the variant mechanism of -Z39.50-1995. - - - -The following is an example of a title element which occurs in two -different languages. - - - - - -<title> - <var lang lang "eng"> - Zen and the Art of Motorcycle Maintenance</> - <var lang lang "dan"> - Zen og Kunsten at Vedligeholde en Motorcykel</> -</title> - - - - - -The syntax of the variant element is <var class -type value>. The available values for the class and -type fields are given by the variant set that is associated with the -current schema (see section ). - - - -Variant elements are terminated by the general end-tag </>, by -the variant end-tag </var>, by the appearance of another variant -tag with the same class and value settings, or by the -appearance of another, normal tag. In other words, the end-tags for -the variants used in the example above could have been saved. - - - -Variant elements can be nested. The element - - - - - -<title> - <var lang lang "eng"><var body iana "text/plain"> - Zen and the Art of Motorcycle Maintenance -</title> - - - - - -Associates two variant components to the variant list for the title -element. - - - -Given the nesting rules described above, we could write - - - - - -<title> - <var body iana "text/plain> - <var lang lang "eng"> - Zen and the Art of Motorcycle Maintenance - <var lang lang "dan"> - Zen og Kunsten at Vedligeholde en Motorcykel -</title> - - - - - -The title element above comes in two variants. Both have the IANA body -type "text/plain", but one is in English, and the other in -Danish. The client, using the element selection mechanism of Z39.50, -can retrieve information about the available variant forms of data -elements, or it can select specific variants based on the requirements -of the end-user. - - - - - - - -Input Filters - - -In order to handle general input formats, Zebra allows the -operator to define filters which read individual records in their native format -and produce an internal representation that the system can -work with. - - - -Input filters are ASCII files, generally with the suffix .flt. -The system looks for the files in the directories given in the -profilePath setting in the zebra.cfg files. The record type -for the filter is grs.regx.filter-filename -(fundamental type grs, file read type regx, argument -filter-filename). - - - -Generally, an input filter consists of a sequence of rules, where each -rule consists of a sequence of expressions, followed by an action. The -expressions are evaluated against the contents of the input record, -and the actions normally contribute to the generation of an internal -representation of the record. - - - -An expression can be either of the following: - - - - - - -INIT - - -The action associated with this expression is evaluated -exactly once in the lifetime of the application, before any records -are read. It can be used in conjunction with an action that -initializes tables or other resources that are used in the processing -of input records. - - - - -BEGIN - - -Matches the beginning of the record. It can be used to -initialize variables, etc. Typically, the BEGIN rule is also used -to establish the root node of the record. - - - - -END - - -Matches the end of the record - when all of the contents -of the record has been processed. - - - - -/pattern/ - - -Matches a string of characters from the input -record. - - - - -BODY - - -This keyword may only be used between two patterns. It -matches everything between (not including) those patterns. - - - - -FINISH - - -The expression asssociated with this pattern is evaluated -once, before the application terminates. It can be used to release -system resources - typically ones allocated in the INIT step. - - - - - - - -An action is surrounded by curly braces ({...}), and consists of a -sequence of statements. Statements may be separated by newlines or -semicolons (;). Within actions, the strings that matched the -expressions immediately preceding the action can be referred to as -$0, $1, $2, etc. - - - -The available statements are: - - - - - - -begin type [parameter ... ] - - -Begin a new -data element. The type is one of the following: - - - -record - - -Begin a new record. The followingparameter should be the -name of the schema that describes the structure of the record, eg. -gils or wais (see below). The begin record call should -precede -any other use of the begin statement. - - - - -element - - -Begin a new tagged element. The parameter is the -name of the tag. If the tag is not matched anywhere in the tagsets -referenced by the current schema, it is treated as a local string -tag. - - - - -variant - - -Begin a new node in a variant tree. The parameters are -class type value. - - - - - - - - -data - - -Create a data element. The concatenated arguments make -up the value of the data element. The option -text signals that -the layout (whitespace) of the data should be retained for -transmission. The option -element tag wraps the data up in -the tag. The use of the -element option is equivalent to -preceding the command with a begin element command, and following -it with the end command. - - - - -end [type] - - -Close a tagged element. If no parameter is given, -the last element on the stack is terminated. The first parameter, if -any, is a type name, similar to the begin statement. For the -element type, a tag name can be provided to terminate a specific tag. - - - - - - - -The following input filter reads a Usenet news file, producing a -record in the WAIS schema. Note that the body of a news posting is -separated from the list of headers by a blank line (or rather a -sequence of two newline characters. - - - - - -BEGIN { begin record wais } - -/^From:/ BODY /$/ { data -element name $1 } -/^Subject:/ BODY /$/ { data -element title $1 } -/^Date:/ BODY /$/ { data -element lastModified $1 } -/\n\n/ BODY END { - begin element bodyOfDisplay - begin variant body iana "text/plain" - data -text $1 - end record - } - - - - - -If Zebra is compiled with support for Tcl (Tool Command Language) -enabled, the statements described above are supplemented with a complete -scripting environment, including control structures (conditional -expressions and loop constructs), and powerful string manipulation -mechanisms for modifying the elements of a record. Tcl is a popular -scripting environment, with several tutorials available both online -and in hardcopy. - - - -NOTE: Tcl support is not currently available, but will be -included with one of the next alpha or beta releases. - - - -NOTE: Variant support is not currently available in the input -filter, but will be included with one of the next alpha or beta -releases. - - - - - - - -Internal Representation - - -When records are manipulated by the system, they're represented in a -tree-structure, with data elements at the leaf nodes, and tags or -variant components at the non-leaf nodes. The root-node identifies the -schema that lends context to the tagging and structuring of the -record. Imagine a simple record, consisting of a 'title' element and -an 'author' element: - - - - - - TITLE "Zen and the Art of Motorcycle Maintenance" -ROOT - AUTHOR "Robert Pirsig" - - - - - -A slightly more complex record would have the author element consist -of two elements, a surname and a first name: - - - - - - TITLE "Zen and the Art of Motorcycle Maintenance" -ROOT - FIRST-NAME "Robert" - AUTHOR - SURNAME "Pirsig" - - - - - -The root of the record will refer to the record schema that describes -the structuring of this particular record. The schema defines the -element tags (TITLE, FIRST-NAME, etc.) that may occur in the record, as -well as the structuring (SURNAME should appear below AUTHOR, etc.). In -addition, the schema establishes element set names that are used by -the client to request a subset of the elements of a given record. The -schema may also establish rules for converting the record to a -different schema, by stating, for each element, a mapping to a -different tag path. - - - -Tagged Elements - - -A data element is characterized by its tag, and its position in the -structure of the record. For instance, while the tag "telephone -number" may be used different places in a record, we may need to -distinguish between these occurrences, both for searching and -presentation purposes. For instance, while the phone numbers for the -"customer" and the "service provider" are both -representatives for the same type of resource (a telephone number), it -is essential that they be kept separate. The record schema provides -the structure of the record, and names each data element (defined by -the sequence of tags - the tag path - by which the element can be -reached from the root of the record). - - - - - -Variants - - -The children of a tag node may be either more tag nodes, a data node -(possibly accompanied by tag nodes), -or a tree of variant nodes. The children of variant nodes are either -more variant nodes or a data node (possibly accompanied by more -variant nodes). Each leaf node, which is normally a -data node, corresponds to a variant form of the tagged element -identified by the tag which parents the variant tree. The following -title element occurs in two different languages: - - - - - - VARIANT LANG=ENG "War and Peace" -TITLE - VARIANT LANG=DAN "Krig og Fred" - - - - - -Which of the two elements are transmitted to the client by the server -depends on the specifications provided by the client, if any. - - - -In practice, each variant node is associated with a triple of class, -type, value, corresponding to the variant mechanism of Z39.50. - - - - - -Data Elements - - -Data nodes have no children (they are always leaf nodes in the record -tree). - - - -NOTE: Documentation needs extension here about types of nodes - numerical, -textual, etc., plus the various types of inclusion notes. - - - - - - - -Configuring Your Data Model - - -The following sections describe the configuration files that govern -the internal management of data records. The system searches for the files -in the directories specified by the profilePath setting in the -zebra.cfg file. - - - -The Abstract Syntax - - -The abstract syntax definition (also known as an Abstract Record -Structure, or ARS) is the focal point of the -record schema description. For a given schema, the ABS file may state any -or all of the following: - - - - - - - - -The object identifier of the Z39.50 schema associated -with the ARS, so that it can be referred to by the client. - - - - - - -The attribute set (which can possibly be a compound of multiple -sets) which applies in the profile. This is used when indexing and -searching the records belonging to the given profile. - - - - - - -The Tag set (again, this can consist of several different sets). -This is used when reading the records from a file, to recognize the -different tags, and when transmitting the record to the client - -mapping the tags to their numerical representation, if they are -known. - - - - - - -The variant set which is used in the profile. This provides a -vocabulary for specifying the forms of data that appear inside -the records. - - - - - - -Element set names, which are a shorthand way for the client to -ask for a subset of the data elements contained in a record. Element -set names, in the retrieval module, are mapped to element -specifications, which contain information equivalent to the -Espec-1 syntax of Z39.50. - - - - - - -Map tables, which may specify mappings to other database -profiles, if desired. - - - - - - -Possibly, a set of rules describing the mapping of elements to a -MARC representation. - - - - - - -A list of element descriptions (this is the actual ARS of the -schema, in Z39.50 terms), which lists the ways in which the various -tags can be used and organized hierarchically. - - - - - - - - -Several of the entries above simply refer to other files, which -describe the given objects. - - - - - -The Configuration Files - - -This section describes the syntax and use of the various tables which -are used by the retrieval module. - - - -The number of different file types may appear daunting at first, but -each type corresponds fairly clearly to a single aspect of the Z39.50 -retrieval facilities. Further, the average database administrator, -who is simply reusing an existing profile for which tables already -exist, shouldn't have to worry too much about the contents of these tables. - - - -Generally, the files are simple ASCII files, which can be maintained -using any text editor. Blank lines, and lines beginning with a (#) are -ignored. Any characters on a line followed by a (#) are also ignored. -All other -lines contain directives, which provide some setting or value -to the system. Generally, settings are characterized by a single -keyword, identifying the setting, followed by a number of parameters. -Some settings are repeatable (r), while others may occur only once in a -file. Some settings are optional (o), whicle others again are -mandatory (m). - - - - - -The Abstract Syntax (.abs) Files - - -The name of this file type is slightly misleading in Z39.50 terms, -since, apart from the actual abstract syntax of the profile, it also -includes most of the other definitions that go into a database -profile. - - - -When a record in the canonical, SGML-like format is read from a file -or from the database, the first tag of the file should reference the -profile that governs the layout of the record. If the first tag of the -record is, say, <gils>, the system will look for the profile -definition in the file gils.abs. Profile definitions are cached, -so they only have to be read once during the lifespan of the current -process. - - - -When writing your own input filters, the record-begin command -introduces the profile, and should always be called first thing when -introducing a new record. - - - -The file may contain the following directives: - - - - - - -name symbolic-name - - -(m) This provides a shorthand name or -description for the profile. Mostly useful for diagnostic purposes. - - - - -reference OID-name - - -(m) The reference name of the OID for -the profile. The reference names can be found in the util -module of YAZ. - - - - -attset filename - - -(m) The attribute set that is used for -indexing and searching records belonging to this profile. - - - - -tagset filename - - -(o) The tag set (if any) that describe -that fields of the records. - - - - -varset filename - - -(o) The variant set used in the profile. - - - - -maptab filename - - -(o,r) This points to a -conversion table that might be used if the client asks for the record -in a different schema from the native one. - - - -marc filename - - -(o) Points to a file containing parameters -for representing the record contents in the ISO2709 syntax. Read the -description of the MARC representation facility below. - - - -esetname name filename - - -(o,r) Associates the -given element set name with an element selection file. If an (@) is -given in place of the filename, this corresponds to a null mapping for -the given element set name. - - - -any tags - - -(o) This directive specifies a list of -attributes which should be appended to the attribute list given for each -element. The effect is to make every single element in the abstract -syntax searchable by way of the given attributes. This directive -provides an efficient way of supporting free-text searching across all -elements. However, it does increase the size of the index -significantly. The attributes can be qualified with a structure, as in -the elm directive below. - - - -elm path name attributes - - -(o,r) Adds an element -to the abstract record syntax of the schema. The path follows the -syntax which is suggested by the Z39.50 document - that is, a sequence -of tags separated by slashes (/). Each tag is given as a -comma-separated pair of tag type and -value surrounded by parenthesis. -The name is the name of the element, and the attributes -specifies which attributes to use when indexing the element in a -comma-separated list. A ! in -place of the attribute name is equivalent to specifying an attribute -name identical to the element name. A - in place of the attribute name -specifies that no indexing is to take place for the given element. The -attributes can be qualified with field types to specify which -character set should govern the indexing procedure for that field. The -same data element may be indexed into several different fields, using -different character set definitions. See the section -. -The default field type is "w" for -word. - - - - - - -NOTE: The mechanism for controlling indexing is not adequate for -complex databases, and will probably be moved into a separate -configuration table eventually. - - - -The following is an excerpt from the abstract syntax file for the GILS -profile. - - - - - -name gils -reference GILS-schema -attset gils.att -tagset gils.tag -varset var1.var - -maptab gils-usmarc.map - -# Element set names - -esetname VARIANT gils-variant.est # for WAIS-compliance -esetname B gils-b.est -esetname G gils-g.est -esetname F @ - -elm (1,10) rank - -elm (1,12) url - -elm (1,14) localControlNumber Local-number -elm (1,16) dateOfLastModification Date/time-last-modified -elm (2,1) title w:!,p:! -elm (4,1) controlIdentifier Identifier-standard -elm (2,6) abstract Abstract -elm (4,51) purpose ! -elm (4,52) originator - -elm (4,53) accessConstraints ! -elm (4,54) useConstraints ! -elm (4,70) availability - -elm (4,70)/(4,90) distributor - -elm (4,70)/(4,90)/(2,7) distributorName ! -elm (4,70)/(4,90)/(2,10 distributorOrganization ! -elm (4,70)/(4,90)/(4,2) distributorStreetAddress ! -elm (4,70)/(4,90)/(4,3) distributorCity ! - - - - - - - -The Attribute Set (.att) Files - - -This file type describes the Use elements of an attribute set. -It contains the following directives. - - - - - - -name symbolic-name - - -(m) This provides a shorthand name or -description for the attribute set. Mostly useful for diagnostic purposes. - - - -reference OID-name - - -(m) The reference name of the OID for -the attribute set. The reference names can be found in the util -module of YAZ. - - - -ordinal integer - - -(m) This value will be used to represent the -attribute set in the index. Care should be taken that each attribute -set has a unique ordinal value. - - - -include filename - - -(o,r) This directive is used to -include another attribute set as a part of the current one. This is -used when a new attribute set is defined as an extension to another -set. For instance, many new attribute sets are defined as extensions -to the bib-1 set. This is an important feature of the retrieval -system of Z39.50, as it ensures the highest possible level of -interoperability, as those access points of your database which are -derived from the external set (say, bib-1) can be used even by clients -who are unaware of the new set. - - - -att att-value att-name [local-value] - - -(o,r) This -repeatable directive introduces a new attribute to the set. The -attribute value is stored in the index (unless a local-value is -given, in which case this is stored). The name is used to refer to the -attribute from the abstract syntax. - - - - - - -This is an excerpt from the GILS attribute set definition. Notice how -the file describing the bib-1 attribute set is referenced. - - - - - -name gils -reference GILS-attset -include bib1.att -ordinal 2 - -att 2001 distributorName -att 2002 indextermsControlled -att 2003 purpose -att 2004 accessConstraints -att 2005 useConstraints - - - - - - - -The Tag Set (.tag) Files - - -This file type defines the tagset of the profile, possibly by -referencing other tag sets (most tag sets, for instance, will include -tagsetG and tagsetM from the Z39.50 specification. The file may -contain the following directives. - - - - - - -name symbolic-name - - -(m) This provides a shorthand name or -description for the tag set. Mostly useful for diagnostic purposes. - - - -reference OID-name - - -(o) The reference name of the OID for -the tag set. The reference names can be found in the util -module of YAZ. The directive is optional, since not all tag sets -are registered outside of their schema. - - - -type integer - - -(m) The type number of the tagset within the schema -profile (note: this specification really should belong to the .abs -file. This will be fixed in a future release). - - - -include filename - - -(o,r) This directive is used -to include the definitions of other tag sets into the current one. - - - -tag number names type - - -(o,r) Introduces a new -tag to the set. The number is the tag number as used in the protocol -(there is currently no mechanism for specifying string tags at this -point, but this would be quick work to add). The names parameter -is a list of names by which the tag should be recognized in the input -file format. The names should be separated by slashes (/). The -type is th recommended datatype of the tag. It should be one of -the following: - - - - - -structured - - - - - -string - - - - - -numeric - - - - - -bool - - - - - -oid - - - - - -generalizedtime - - - - - -intunit - - - - - -int - - - - - -octetstring - - - - - -null - - - - - - - - - - - -The following is an excerpt from the TagsetG definition file. - - - - - -name tagsetg -reference TagsetG -type 2 - -tag 1 title string -tag 2 author string -tag 3 publicationPlace string -tag 4 publicationDate string -tag 5 documentId string -tag 6 abstract string -tag 7 name string -tag 8 date generalizedtime -tag 9 bodyOfDisplay string -tag 10 organization string - - - - - - - -The Variant Set (.var) Files - - -The variant set file is a straightforward representation of the -variant set definitions associated with the protocol. At present, only -the Variant-1 set is known. - - - -These are the directives allowed in the file. - - - - - - -name symbolic-name - - -(m) This provides a shorthand name or -description for the variant set. Mostly useful for diagnostic purposes. - - - -reference OID-name - - -(o) The reference name of the OID for -the variant set, if one is required. The reference names can be found -in the util module of YAZ. - - - -class integer class-name - - -(m,r) Introduces a new -class to the variant set. - - - -type integer type-name datatype - - -(m,r) Addes a -new type to the current class (the one introduced by the most recent -class directive). The type names belong to the same name space as -the one used in the tag set definition file. - - - - - - -The following is an excerpt from the file describing the variant set -Variant-1. - - - - - -name variant-1 -reference Variant-1 - -class 1 variantId - - type 1 variantId octetstring - -class 2 body - - type 1 iana string - type 2 z39.50 string - type 3 other string - - - - - - - -The Element Set (.est) Files - - -The element set specification files describe a selection of a subset -of the elements of a database record. The element selection mechanism -is equivalent to the one supplied by the Espec-1 syntax of the -Z39.50 specification. In fact, the internal representation of an -element set specification is identical to the Espec-1 structure, -and we'll refer you to the description of that structure for most of -the detailed semantics of the directives below. - - - -NOTE: Not all of the Espec-1 functionality has been implemented yet. -The fields that are mentioned below all work as expected, unless -otherwise is noted. - - - -The directives available in the element set file are as follows: - - - - - - -defaultVariantSetId OID-name - - -(o) If variants are used in -the following, this should provide the name of the variantset used -(it's not currently possible to specify a different set in the -individual variant request). In almost all cases (certainly all -profiles known to us), the name Variant-1 should be given here. - - - -defaultVariantRequest variant-request - - -(o) This directive -provides a default variant request for -use when the individual element requests (see below) do not contain a -variant request. Variant requests consist of a blank-separated list of -variant components. A variant compont is a comma-separated, -parenthesized triple of variant class, type, and value (the two former -values being represented as integers). The value can currently only be -entered as a string (this will change to depend on the definition of -the variant in question). The special value (@) is interpreted as a -null value, however. - - - -simpleElement path ['variant' variant-request] - - -(o,r) This corresponds to a simple element request in Espec-1. The -path consists of a sequence of tag-selectors, where each of these can -consist of either: - - - - - - - - -A simple tag, consisting of a comma-separated type-value pair in -parenthesis, possibly followed by a colon (:) followed by an -occurrences-specification (see below). The tag-value can be a number -or a string. If the first character is an apostrophe ('), this forces -the value to be interpreted as a string, even if it appears to be numerical. - - - - - - -A WildThing, represented as a question mark (?), possibly -followed by a colon (:) followed by an occurrences specification (see -below). - - - - - - -A WildPath, represented as an asterisk (*). Note that the last -element of the path should not be a wildPath (wildpaths don't work in -this version). - - - - - - - - -The occurrences-specification can be either the string all, the -string last, or an explicit value-range. The value-range is -represented as an integer (the starting point), possibly followed by a -plus (+) and a second integer (the number of elements, default being -one). - - - -The variant-request has the same syntax as the defaultVariantRequest -above. Note that it may sometimes be useful to give an empty variant -request, simply to disable the default for a specific set of fields -(we aren't certain if this is proper Espec-1, but it works in -this implementation). - - - - - - -The following is an example of an element specification belonging to -the GILS profile. - - - - - -simpleelement (1,10) -simpleelement (1,12) -simpleelement (2,1) -simpleelement (1,14) -simpleelement (4,1) -simpleelement (4,52) - - - - - - - -The Schema Mapping (.map) Files - - -Sometimes, the client might want to receive a database record in -a schema that differs from the native schema of the record. For -instance, a client might only know how to process WAIS records, while -the database record is represented in a more specific schema, such as -GILS. In this module, a mapping of data to one of the MARC formats is -also thought of as a schema mapping (mapping the elements of the -record into fields consistent with the given MARC specification, prior -to actually converting the data to the ISO2709). This use of the -object identifier for USMARC as a schema identifier represents an -overloading of the OID which might not be entirely proper. However, -it represents the dual role of schema and record syntax which -is assumed by the MARC family in Z39.50. - - - -NOTE: The schema-mapping functions are so far limited to a -straightforward mapping of elements. This should be extended with -mechanisms for conversions of the element contents, and conditional -mappings of elements based on the record contents. - - - -These are the directives of the schema mapping file format: - - - - - - -targetName name - - -(m) A symbolic name for the target schema -of the table. Useful mostly for diagnostic purposes. - - - -targetRef OID-name - - -(m) An OID name for the target schema. -This is used, for instance, by a server receiving a request to present -a record in a different schema from the native one. The name, again, -is found in the oid module of YAZ. - - - -map element-name target-path - - -(o,r) Adds -an element mapping rule to the table. - - - - - - - - -The MARC (ISO2709) Representation (.mar) Files - - -This file provides rules for representing a record in the ISO2709 -format. The rules pertain mostly to the values of the constant-length -header of the record. - - - -NOTE: This will be described better. We're in the process of -re-evaluating and most likely changing the way that MARC records are -handled by the system. - - - - - -Field Structure and Character Sets - - - -In order to provide a flexible approach to national character set -handling, Zebra allows the administrator to configure the set up the -system to handle any 8-bit character set — including sets that -require multi-octet diacritics or other multi-octet characters. The -definition of a character set includes a specification of the -permissible values, their sort order (this affects the display in the -SCAN function), and relationships between upper- and lowercase -characters. Finally, the definition includes the specification of -space characters for the set. - - - -The operator can define different character sets for different fields, -typical examples being standard text fields, numerical fields, and -special-purpose fields such as WWW-style linkages (URx). - - - -The field types, and hence character sets, are associated with data -elements by the .abs files (see above). The file default.idx -provides the association between field type codes (as used in the .abs -files) and the character map files (with the .chr suffix). The format -of the .idx file is as follows - - - - - - -index field type code - - -This directive introduces a new -search index code. The argument is a one-character code to be used in the -.abs files to select this particular index type. An index, roughly, -corresponds to a particular structure attribute during search. Refer -to section . - - - -sort field code type - - -This directive introduces a -sort index. The argument is a one-character code to be used in the -.abs fie to select this particular index type. The corresponding -use attribute must be used in the sort request to refer to this -particular sort index. The corresponding character map (see below) -is used in the sort process. - - - -completeness boolean - - -This directive enables or disables -complete field indexing. The value of the boolean should be 0 -(disable) or 1. If completeness is enabled, the index entry will -contain the complete contents of the field (up to a limit), with words -(non-space characters) separated by single space characters -(normalized to " " on display). When completeness is -disabled, each word is indexed as a separate entry. Complete subfield -indexing is most useful for fields which are typically browsed (eg. -titles, authors, or subjects), or instances where a match on a -complete subfield is essential (eg. exact title searching). For fields -where completeness is disabled, the search engine will interpret a -search containing space characters as a word proximity search. - - - -charmap filename - - -This is the filename of the character -map to be used for this index for field type. - - - - - - -The contents of the character map files are structured as follows: - - - - - - -lowercase value-set - - -This directive introduces the basic -value set of the field type. The format is an ordered list (without -spaces) of the characters which may occur in "words" of -the given type. The order of the entries in the list determines the -sort order of the index. In addition to single characters, the -following combinations are legal: - - - - - - - - -Backslashes may be used to introduce three-digit octal, or -two-digit hex representations of single characters (preceded by x). -In addition, the combinations -\\, \\r, \\n, \\t, \\s (space — remember that real space-characters -may ot occur in the value definition), and \\ are recognised, -with their usual interpretation. - - - - - - -Curly braces {} may be used to enclose ranges of single -characters (possibly using the escape convention described in the -preceding point), eg. {a-z} to entroduce the standard range of ASCII -characters. Note that the interpretation of such a range depends on -the concrete representation in your local, physical character set. - - - - - - -paranthesises () may be used to enclose multi-byte characters - -eg. diacritics or special national combinations (eg. Spanish -"ll"). When found in the input stream (or a search term), -these characters are viewed and sorted as a single character, with a -sorting value depending on the position of the group in the value -statement. - - - - - - - - -uppercase value-set - - -This directive introduces the -upper-case equivalencis to the value set (if any). The number and -order of the entries in the list should be the same as in the -lowercase directive. - - - -space value-set - - -This directive introduces the character -which separate words in the input stream. Depending on the -completeness mode of the field in question, these characters either -terminate an index entry, or delimit individual "words" in -the input stream. The order of the elements is not significant — -otherwise the representation is the same as for the upercase and -lowercase directives. - - - -map value-set target - - -This directive introduces a -mapping between each of the members of the value-set on the left to -the character on the right. The character on the right must occur in -the value set (the lowercase directive) of the character set, but -it may be a paranthesis-enclosed multi-octet character. This directive -may be used to map diacritics to their base characters, or to map -HTML-style character-representations to their natural form, etc. - - - - - - - - - - -Exchange Formats - - -Converting records from the internal structure to en exchange format -is largely an automatic process. Currently, the following exchange -formats are supported: - - - - - - - - -GRS-1. The internal representation is based on GRS-1, so the -conversion here is straightforward. The system will create -applied variant and supported variant lists as required, if a record -contains variant information. - - - - - - -SUTRS. Again, the mapping is fairly straighforward. Indentation -is used to show the hierarchical structure of the record. All -"GRS" type records support both the GRS-1 and SUTRS -representations. - - - - - - -ISO2709-based formats (USMARC, etc.). Only records with a -two-level structure (corresponding to fields and subfields) can be -directly mapped to ISO2709. For records with a different structuring -(eg., GILS), the representation in a structure like USMARC involves a -schema-mapping (see section ), to an -"implied" USMARC schema (implied, -because there is no formal schema which specifies the use of the -USMARC fields outside of ISO2709). The resultant, two-level record is -then mapped directly from the internal representation to ISO2709. See -the GILS schema definition files for a detailed example of this -approach. - - - - - - -Explain. This representation is only available for records -belonging to the Explain schema. - - - - - - -Summary. This ASN-1 based structure is only available for records -belonging to the Summary schema - or schema which provide a mapping -to this schema (see the description of the schema mapping facility -above). - - - - - - -SOIF. Support for this syntax is experimental, and is currently -keyed to a private Index Data OID (1.2.840.10003.5.1000.81.2). All -abstract syntaxes can be mapped to the SOIF format, although nested -elements are represented by concatenation of the tag names at each -level. - - - - - - - - - + + <title> + <var body iana "text/plain> + <var lang lang "eng"> + Zen and the Art of Motorcycle Maintenance + <var lang lang "dan"> + Zen og Kunsten at Vedligeholde en Motorcykel + </title> + + + + + + The title element above comes in two variants. Both have the IANA body + type "text/plain", but one is in English, and the other in + Danish. The client, using the element selection mechanism of Z39.50, + can retrieve information about the available variant forms of data + elements, or it can select specific variants based on the requirements + of the end-user. + + + + + + + + Input Filters + + + In order to handle general input formats, Zebra allows the + operator to define filters which read individual records in their + native format and produce an internal representation that the system + can work with. + + + + Input filters are ASCII files, generally with the suffix + .flt. + The system looks for the files in the directories given in the + profilePath setting in the + zebra.cfg files. + The record type for the filter is + grs.regx.filter-filename + (fundamental type grs, file read + type regx, argument + filter-filename). + + + + Generally, an input filter consists of a sequence of rules, where each + rule consists of a sequence of expressions, followed by an action. The + expressions are evaluated against the contents of the input record, + and the actions normally contribute to the generation of an internal + representation of the record. + + + + An expression can be either of the following: + + + + + + + INIT + + + The action associated with this expression is evaluated + exactly once in the lifetime of the application, before any records + are read. It can be used in conjunction with an action that + initializes tables or other resources that are used in the processing + of input records. + + + + + BEGIN + + + Matches the beginning of the record. It can be used to + initialize variables, etc. Typically, the + BEGIN rule is also used + to establish the root node of the record. + + + + + END + + + Matches the end of the record - when all of the contents + of the record has been processed. + + + + + /pattern/ + + + Matches a string of characters from the input record. + + + + + BODY + + + This keyword may only be used between two patterns. + It matches everything between (not including) those patterns. + + + + + FINISH + + + The expression asssociated with this pattern is evaluated + once, before the application terminates. It can be used to release + system resources - typically ones allocated in the + INIT step. + + + + + + + + An action is surrounded by curly braces ({...}), and + consists of a sequence of statements. Statements may be separated + by newlines or semicolons (;). + Within actions, the strings that matched the expressions + immediately preceding the action can be referred to as + $0, $1, $2, etc. + + + + The available statements are: + + + + + + + begin type [parameter ... ] + + + Begin a new + data element. The type is one of the following: + + + + record + + + Begin a new record. The followingparameter should be the + name of the schema that describes the structure of the record, eg. + gils or wais (see below). + The begin record call should precede + any other use of the begin statement. + + + + + element + + + Begin a new tagged element. The parameter is the + name of the tag. If the tag is not matched anywhere in the tagsets + referenced by the current schema, it is treated as a local string + tag. + + + + + variant + + + Begin a new node in a variant tree. The parameters are + class type value. + + + + + + + + + data + + + Create a data element. The concatenated arguments make + up the value of the data element. + The option -text signals that + the layout (whitespace) of the data should be retained for + transmission. + The option -element + tag wraps the data up in + the tag. + The use of the -element option is equivalent to + preceding the command with a begin + element command, and following + it with the end command. + + + + + end [type] + + + Close a tagged element. If no parameter is given, + the last element on the stack is terminated. + The first parameter, if any, is a type name, similar + to the begin statement. + For the element type, a tag + name can be provided to terminate a specific tag. + + + + + + + + The following input filter reads a Usenet news file, producing a + record in the WAIS schema. Note that the body of a news posting is + separated from the list of headers by a blank line (or rather a + sequence of two newline characters. + + + + + + BEGIN { begin record wais } + + /^From:/ BODY /$/ { data -element name $1 } + /^Subject:/ BODY /$/ { data -element title $1 } + /^Date:/ BODY /$/ { data -element lastModified $1 } + /\n\n/ BODY END { + begin element bodyOfDisplay + begin variant body iana "text/plain" + data -text $1 + end record + } + + + + + + If Zebra is compiled with support for Tcl (Tool Command Language) + enabled, the statements described above are supplemented with a complete + scripting environment, including control structures (conditional + expressions and loop constructs), and powerful string manipulation + mechanisms for modifying the elements of a record. Tcl is a popular + scripting environment, with several tutorials available both online + and in hardcopy. + + + + NOTE: Tcl support is not currently available, but will be + included with one of the next alpha or beta releases. + + + + NOTE: Variant support is not currently available in the input + filter, but will be included with one of the next alpha or beta + releases. + + + + + + + + Internal Representation + + + When records are manipulated by the system, they're represented in a + tree-structure, with data elements at the leaf nodes, and tags or + variant components at the non-leaf nodes. The root-node identifies the + schema that lends context to the tagging and structuring of the + record. Imagine a simple record, consisting of a 'title' element and + an 'author' element: + + + + + + TITLE "Zen and the Art of Motorcycle Maintenance" + ROOT + AUTHOR "Robert Pirsig" + + + + + + A slightly more complex record would have the author element consist + of two elements, a surname and a first name: + + + + + + TITLE "Zen and the Art of Motorcycle Maintenance" + ROOT + FIRST-NAME "Robert" + AUTHOR + SURNAME "Pirsig" + + + + + + The root of the record will refer to the record schema that describes + the structuring of this particular record. The schema defines the + element tags (TITLE, FIRST-NAME, etc.) that may occur in the record, as + well as the structuring (SURNAME should appear below AUTHOR, etc.). In + addition, the schema establishes element set names that are used by + the client to request a subset of the elements of a given record. The + schema may also establish rules for converting the record to a + different schema, by stating, for each element, a mapping to a + different tag path. + + + + Tagged Elements + + + A data element is characterized by its tag, and its position in the + structure of the record. For instance, while the tag "telephone + number" may be used different places in a record, we may need to + distinguish between these occurrences, both for searching and + presentation purposes. For instance, while the phone numbers for the + "customer" and the "service provider" are both + representatives for the same type of resource (a telephone number), it + is essential that they be kept separate. The record schema provides + the structure of the record, and names each data element (defined by + the sequence of tags - the tag path - by which the element can be + reached from the root of the record). + + + + + + Variants + + + The children of a tag node may be either more tag nodes, a data node + (possibly accompanied by tag nodes), + or a tree of variant nodes. The children of variant nodes are either + more variant nodes or a data node (possibly accompanied by more + variant nodes). Each leaf node, which is normally a + data node, corresponds to a variant form of the + tagged element identified by the tag which parents the variant tree. + The following title element occurs in two different languages: + + + + + + VARIANT LANG=ENG "War and Peace" + TITLE + VARIANT LANG=DAN "Krig og Fred" + + + + + + Which of the two elements are transmitted to the client by the server + depends on the specifications provided by the client, if any. + + + + In practice, each variant node is associated with a triple of class, + type, value, corresponding to the variant mechanism of Z39.50. + + + + + + Data Elements + + + Data nodes have no children (they are always leaf nodes in the record + tree). + + + + + Documentation needs extension here about types of nodes - numerical, + textual, etc., plus the various types of inclusion notes. + + + + + + + + + Configuring Your Data Model + + + The following sections describe the configuration files that govern + the internal management of data records. The system searches for the files + in the directories specified by the profilePath + setting in the zebra.cfg file. + + + + The Abstract Syntax + + + The abstract syntax definition (also known as an Abstract Record + Structure, or ARS) is the focal point of the + record schema description. For a given schema, the ABS file may state any + or all of the following: + + + + + + + + + The object identifier of the Z39.50 schema associated + with the ARS, so that it can be referred to by the client. + + + + + + The attribute set (which can possibly be a compound of multiple + sets) which applies in the profile. This is used when indexing and + searching the records belonging to the given profile. + + + + + + The Tag set (again, this can consist of several different sets). + This is used when reading the records from a file, to recognize the + different tags, and when transmitting the record to the client - + mapping the tags to their numerical representation, if they are + known. + + + + + + The variant set which is used in the profile. This provides a + vocabulary for specifying the forms of data that appear inside + the records. + + + + + + Element set names, which are a shorthand way for the client to + ask for a subset of the data elements contained in a record. Element + set names, in the retrieval module, are mapped to element + specifications, which contain information equivalent to the + Espec-1 syntax of Z39.50. + + + + + + Map tables, which may specify mappings to + other database profiles, if desired. + + + + + + Possibly, a set of rules describing the mapping of elements to a + MARC representation. + + + + + + + A list of element descriptions (this is the actual ARS of the + schema, in Z39.50 terms), which lists the ways in which the various + tags can be used and organized hierarchically. + + + + + + + + + Several of the entries above simply refer to other files, which + describe the given objects. + + + + + + The Configuration Files + + + This section describes the syntax and use of the various tables which + are used by the retrieval module. + + + + The number of different file types may appear daunting at first, but + each type corresponds fairly clearly to a single aspect of the Z39.50 + retrieval facilities. Further, the average database administrator, + who is simply reusing an existing profile for which tables already + exist, shouldn't have to worry too much about the contents of these tables. + + + + Generally, the files are simple ASCII files, which can be maintained + using any text editor. Blank lines, and lines beginning with a (#) are + ignored. Any characters on a line followed by a (#) are also ignored. + All other lines contain directives, which provide + some setting or value to the system. + Generally, settings are characterized by a single + keyword, identifying the setting, followed by a number of parameters. + Some settings are repeatable (r), while others may occur only once in a + file. Some settings are optional (o), whicle others again are + mandatory (m). + + + + + + The Abstract Syntax (.abs) Files + + + The name of this file type is slightly misleading in Z39.50 terms, + since, apart from the actual abstract syntax of the profile, it also + includes most of the other definitions that go into a database + profile. + + + + When a record in the canonical, SGML-like format is read from a file + or from the database, the first tag of the file should reference the + profile that governs the layout of the record. If the first tag of the + record is, say, <gils>, the system will look + for the profile definition in the file gils.abs. + Profile definitions are cached, so they only have to be read once + during the lifespan of the current process. + + + + When writing your own input filters, the + record-begin command + introduces the profile, and should always be called first thing when + introducing a new record. + + + + The file may contain the following directives: + + + + + + + name symbolic-name + + + (m) This provides a shorthand name or + description for the profile. Mostly useful for diagnostic purposes. + + + + + reference OID-name + + + (m) The reference name of the OID for the profile. + The reference names can be found in the util + module of YAZ. + + + + + attset filename + + + (m) The attribute set that is used for + indexing and searching records belonging to this profile. + + + + + tagset filename + + + (o) The tag set (if any) that describe + that fields of the records. + + + + + varset filename + + + (o) The variant set used in the profile. + + + + + maptab filename + + + (o,r) This points to a + conversion table that might be used if the client asks for the record + in a different schema from the native one. + + + + marc filename + + + (o) Points to a file containing parameters + for representing the record contents in the ISO2709 syntax. Read the + description of the MARC representation facility below. + + + + esetname name filename + + + (o,r) Associates the + given element set name with an element selection file. If an (@) is + given in place of the filename, this corresponds to a null mapping for + the given element set name. + + + + any tags + + + (o) This directive specifies a list of attributes + which should be appended to the attribute list given for each + element. The effect is to make every single element in the abstract + syntax searchable by way of the given attributes. This directive + provides an efficient way of supporting free-text searching across all + elements. However, it does increase the size of the index + significantly. The attributes can be qualified with a structure, as in + the elm directive below. + + + + elm path name attributes + + + (o,r) Adds an element to the abstract record syntax of the schema. + The path follows the + syntax which is suggested by the Z39.50 document - that is, a sequence + of tags separated by slashes (/). Each tag is given as a + comma-separated pair of tag type and -value surrounded by parenthesis. + The name is the name of the element, and + the attributes + specifies which attributes to use when indexing the element in a + comma-separated list. + A ! in place of the attribute name is equivalent to + specifying an attribute name identical to the element name. + A - in place of the attribute name + specifies that no indexing is to take place for the given element. + The attributes can be qualified with field + types to specify which + character set should govern the indexing procedure for that field. + The same data element may be indexed into several different + fields, using different character set definitions. + See the section . + The default field type is "w" for word. + + + + + + + + The mechanism for controlling indexing is not adequate for + complex databases, and will probably be moved into a separate + configuration table eventually. + + + + + The following is an excerpt from the abstract syntax file for the GILS + profile. + + + + + + name gils + reference GILS-schema + attset gils.att + tagset gils.tag + varset var1.var + + maptab gils-usmarc.map + + # Element set names + + esetname VARIANT gils-variant.est # for WAIS-compliance + esetname B gils-b.est + esetname G gils-g.est + esetname F @ + + elm (1,10) rank - + elm (1,12) url - + elm (1,14) localControlNumber Local-number + elm (1,16) dateOfLastModification Date/time-last-modified + elm (2,1) title w:!,p:! + elm (4,1) controlIdentifier Identifier-standard + elm (2,6) abstract Abstract + elm (4,51) purpose ! + elm (4,52) originator - + elm (4,53) accessConstraints ! + elm (4,54) useConstraints ! + elm (4,70) availability - + elm (4,70)/(4,90) distributor - + elm (4,70)/(4,90)/(2,7) distributorName ! + elm (4,70)/(4,90)/(2,10 distributorOrganization ! + elm (4,70)/(4,90)/(4,2) distributorStreetAddress ! + elm (4,70)/(4,90)/(4,3) distributorCity ! + + + + + + + + The Attribute Set (.att) Files + + + This file type describes the Use elements of + an attribute set. + It contains the following directives. + + + + + + name symbolic-name + + + (m) This provides a shorthand name or + description for the attribute set. + Mostly useful for diagnostic purposes. + + + + reference OID-name + + + (m) The reference name of the OID for + the attribute set. + The reference names can be found in the util + module of YAZ. + + + + include filename + + + (o,r) This directive is used to + include another attribute set as a part of the current one. This is + used when a new attribute set is defined as an extension to another + set. For instance, many new attribute sets are defined as extensions + to the bib-1 set. + This is an important feature of the retrieval + system of Z39.50, as it ensures the highest possible level of + interoperability, as those access points of your database which are + derived from the external set (say, bib-1) can be used even by clients + who are unaware of the new set. + + + + att + att-value att-name [local-value] + + + (o,r) This + repeatable directive introduces a new attribute to the set. The + attribute value is stored in the index (unless a + local-value is + given, in which case this is stored). The name is used to refer to the + attribute from the abstract syntax. + + + + + + + This is an excerpt from the GILS attribute set definition. + Notice how the file describing the bib-1 + attribute set is referenced. + + + + + + name gils + reference GILS-attset + include bib1.att + + att 2001 distributorName + att 2002 indextermsControlled + att 2003 purpose + att 2004 accessConstraints + att 2005 useConstraints + + + + + + + + The Tag Set (.tag) Files + + + This file type defines the tagset of the profile, possibly by + referencing other tag sets (most tag sets, for instance, will include + tagsetG and tagsetM from the Z39.50 specification. The file may + contain the following directives. + + + + + + + name symbolic-name + + + (m) This provides a shorthand name or + description for the tag set. Mostly useful for diagnostic purposes. + + + + reference OID-name + + + (o) The reference name of the OID for the tag set. + The reference names can be found in the util + module of YAZ. + The directive is optional, since not all tag sets + are registered outside of their schema. + + + + type integer + + + (m) The type number of the tagset within the schema + profile (note: this specification really should belong to the .abs + file. This will be fixed in a future release). + + + + include filename + + + (o,r) This directive is used + to include the definitions of other tag sets into the current one. + + + + tag number names type + + + (o,r) Introduces a new tag to the set. + The number is the tag number as used + in the protocol (there is currently no mechanism for + specifying string tags at this point, but this would be quick + work to add). + The names parameter is a list of names + by which the tag should be recognized in the input file format. + The names should be separated by slashes (/). + The type is th recommended datatype of + the tag. + It should be one of the following: + + + + + structured + + + + + + string + + + + + + numeric + + + + + + bool + + + + + + oid + + + + + + generalizedtime + + + + + + intunit + + + + + + int + + + + + + octetstring + + + + + + null + + + + + + + + + + + + The following is an excerpt from the TagsetG definition file. + + + + + name tagsetg + reference TagsetG + type 2 + + tag 1 title string + tag 2 author string + tag 3 publicationPlace string + tag 4 publicationDate string + tag 5 documentId string + tag 6 abstract string + tag 7 name string + tag 8 date generalizedtime + tag 9 bodyOfDisplay string + tag 10 organization string + + + + + + + The Variant Set (.var) Files + + + The variant set file is a straightforward representation of the + variant set definitions associated with the protocol. At present, only + the Variant-1 set is known. + + + + These are the directives allowed in the file. + + + + + + + name symbolic-name + + + (m) This provides a shorthand name or + description for the variant set. Mostly useful for diagnostic purposes. + + + + reference OID-name + + + (o) The reference name of the OID for + the variant set, if one is required. The reference names can be found + in the util module of YAZ. + + + + class integer class-name + + + (m,r) Introduces a new + class to the variant set. + + + + type integer type-name datatype + + + (m,r) Addes a + new type to the current class (the one introduced by the most recent + class directive). + The type names belong to the same name space as the one used + in the tag set definition file. + + + + + + + The following is an excerpt from the file describing the variant set + Variant-1. + + + + + + name variant-1 + reference Variant-1 + + class 1 variantId + + type 1 variantId octetstring + + class 2 body + + type 1 iana string + type 2 z39.50 string + type 3 other string + + + + + + + + The Element Set (.est) Files + + + The element set specification files describe a selection of a subset + of the elements of a database record. The element selection mechanism + is equivalent to the one supplied by the Espec-1 + syntax of the Z39.50 specification. + In fact, the internal representation of an element set + specification is identical to the Espec-1 structure, + and we'll refer you to the description of that structure for most of + the detailed semantics of the directives below. + + + + + Not all of the Espec-1 functionality has been implemented yet. + The fields that are mentioned below all work as expected, unless + otherwise is noted. + + + + + The directives available in the element set file are as follows: + + + + + + defaultVariantSetId OID-name + + + (o) If variants are used in + the following, this should provide the name of the variantset used + (it's not currently possible to specify a different set in the + individual variant request). In almost all cases (certainly all + profiles known to us), the name + Variant-1 should be given here. + + + + defaultVariantRequest variant-request + + + (o) This directive + provides a default variant request for + use when the individual element requests (see below) do not contain a + variant request. Variant requests consist of a blank-separated list of + variant components. A variant compont is a comma-separated, + parenthesized triple of variant class, type, and value (the two former + values being represented as integers). The value can currently only be + entered as a string (this will change to depend on the definition of + the variant in question). The special value (@) is interpreted as a + null value, however. + + + + simpleElement + path ['variant' variant-request] + + + (o,r) This corresponds to a simple element request + in Espec-1. + The path consists of a sequence of tag-selectors, where each of + these can consist of either: + + + + + + + A simple tag, consisting of a comma-separated type-value pair in + parenthesis, possibly followed by a colon (:) followed by an + occurrences-specification (see below). The tag-value can be a number + or a string. If the first character is an apostrophe ('), this + forces the value to be interpreted as a string, even if it + appears to be numerical. + + + + + + A WildThing, represented as a question mark (?), possibly + followed by a colon (:) followed by an occurrences + specification (see below). + + + + + + A WildPath, represented as an asterisk (*). Note that the last + element of the path should not be a wildPath (wildpaths don't + work in this version). + + + + + + + + + The occurrences-specification can be either the string + all, the string last, or + an explicit value-range. The value-range is represented as + an integer (the starting point), possibly followed by a + plus (+) and a second integer (the number of elements, default + being one). + + + + The variant-request has the same syntax as the defaultVariantRequest + above. Note that it may sometimes be useful to give an empty variant + request, simply to disable the default for a specific set of fields + (we aren't certain if this is proper Espec-1, + but it works in this implementation). + + + + + + + The following is an example of an element specification belonging to + the GILS profile. + + + + + + simpleelement (1,10) + simpleelement (1,12) + simpleelement (2,1) + simpleelement (1,14) + simpleelement (4,1) + simpleelement (4,52) + + + + + + + + The Schema Mapping (.map) Files + + + Sometimes, the client might want to receive a database record in + a schema that differs from the native schema of the record. For + instance, a client might only know how to process WAIS records, while + the database record is represented in a more specific schema, such as + GILS. In this module, a mapping of data to one of the MARC formats is + also thought of as a schema mapping (mapping the elements of the + record into fields consistent with the given MARC specification, prior + to actually converting the data to the ISO2709). This use of the + object identifier for USMARC as a schema identifier represents an + overloading of the OID which might not be entirely proper. However, + it represents the dual role of schema and record syntax which + is assumed by the MARC family in Z39.50. + + + + NOTE: The schema-mapping functions are so far limited to a + straightforward mapping of elements. This should be extended with + mechanisms for conversions of the element contents, and conditional + mappings of elements based on the record contents. + + + + These are the directives of the schema mapping file format: + + + + + + + targetName name + + + (m) A symbolic name for the target schema + of the table. Useful mostly for diagnostic purposes. + + + + targetRef OID-name + + + (m) An OID name for the target schema. + This is used, for instance, by a server receiving a request to present + a record in a different schema from the native one. + The name, again, is found in the oid + module of YAZ. + + + + map element-name target-path + + + (o,r) Adds + an element mapping rule to the table. + + + + + + + + + The MARC (ISO2709) Representation (.mar) Files + + + This file provides rules for representing a record in the ISO2709 + format. The rules pertain mostly to the values of the constant-length + header of the record. + + + + NOTE: This will be described better. We're in the process of + re-evaluating and most likely changing the way that MARC records are + handled by the system. + + + + + + Field Structure and Character Sets + + + + In order to provide a flexible approach to national character set + handling, Zebra allows the administrator to configure the set up the + system to handle any 8-bit character set — including sets that + require multi-octet diacritics or other multi-octet characters. The + definition of a character set includes a specification of the + permissible values, their sort order (this affects the display in the + SCAN function), and relationships between upper- and lowercase + characters. Finally, the definition includes the specification of + space characters for the set. + + + + The operator can define different character sets for different fields, + typical examples being standard text fields, numerical fields, and + special-purpose fields such as WWW-style linkages (URx). + + + + The field types, and hence character sets, are associated with data + elements by the .abs files (see above). + The file default.idx + provides the association between field type codes (as used in the .abs + files) and the character map files (with the .chr suffix). The format + of the .idx file is as follows + + + + + + + index field type code + + + This directive introduces a new search index code. + The argument is a one-character code to be used in the + .abs files to select this particular index type. An index, roughly, + corresponds to a particular structure attribute during search. Refer + to section . + + + + sort field code type + + + This directive introduces a + sort index. The argument is a one-character code to be used in the + .abs fie to select this particular index type. The corresponding + use attribute must be used in the sort request to refer to this + particular sort index. The corresponding character map (see below) + is used in the sort process. + + + + completeness boolean + + + This directive enables or disables complete field indexing. + The value of the boolean should be 0 + (disable) or 1. If completeness is enabled, the index entry will + contain the complete contents of the field (up to a limit), with words + (non-space characters) separated by single space characters + (normalized to " " on display). When completeness is + disabled, each word is indexed as a separate entry. Complete subfield + indexing is most useful for fields which are typically browsed (eg. + titles, authors, or subjects), or instances where a match on a + complete subfield is essential (eg. exact title searching). For fields + where completeness is disabled, the search engine will interpret a + search containing space characters as a word proximity search. + + + + charmap filename + + + This is the filename of the character + map to be used for this index for field type. + + + + + + + The contents of the character map files are structured as follows: + + + + + + + lowercase value-set + + + This directive introduces the basic value set of the field type. + The format is an ordered list (without spaces) of the + characters which may occur in "words" of the given type. + The order of the entries in the list determines the + sort order of the index. In addition to single characters, the + following combinations are legal: + + + + + + + + Backslashes may be used to introduce three-digit octal, or + two-digit hex representations of single characters + (preceded by x). + In addition, the combinations + \\, \\r, \\n, \\t, \\s (space — remember that real + space-characters may ot occur in the value definition), and + \\ are recognised, with their usual interpretation. + + + + + + Curly braces {} may be used to enclose ranges of single + characters (possibly using the escape convention described in the + preceding point), eg. {a-z} to entroduce the + standard range of ASCII characters. + Note that the interpretation of such a range depends on + the concrete representation in your local, physical character set. + + + + + + paranthesises () may be used to enclose multi-byte characters - + eg. diacritics or special national combinations (eg. Spanish + "ll"). When found in the input stream (or a search term), + these characters are viewed and sorted as a single character, with a + sorting value depending on the position of the group in the value + statement. + + + + + + + + + uppercase value-set + + + This directive introduces the + upper-case equivalencis to the value set (if any). The number and + order of the entries in the list should be the same as in the + lowercase directive. + + + + space value-set + + + This directive introduces the character + which separate words in the input stream. Depending on the + completeness mode of the field in question, these characters either + terminate an index entry, or delimit individual "words" in + the input stream. The order of the elements is not significant — + otherwise the representation is the same as for the + uppercase and lowercase + directives. + + + + map value-set + target + + + This directive introduces a + mapping between each of the members of the value-set on the left to + the character on the right. The character on the right must occur in + the value set (the lowercase directive) of + the character set, but + it may be a paranthesis-enclosed multi-octet character. This directive + may be used to map diacritics to their base characters, or to map + HTML-style character-representations to their natural form, etc. + + + + + + + + + + + Exchange Formats + + + Converting records from the internal structure to en exchange format + is largely an automatic process. Currently, the following exchange + formats are supported: + + + + + + + GRS-1. The internal representation is based on GRS-1, so the + conversion here is straightforward. The system will create + applied variant and supported variant lists as required, if a record + contains variant information. + + + + + + SUTRS. Again, the mapping is fairly straighforward. Indentation + is used to show the hierarchical structure of the record. All + "GRS" type records support both the GRS-1 and SUTRS + representations. + + + + + + ISO2709-based formats (USMARC, etc.). Only records with a + two-level structure (corresponding to fields and subfields) can be + directly mapped to ISO2709. For records with a different structuring + (eg., GILS), the representation in a structure like USMARC involves a + schema-mapping (see section ), to an + "implied" USMARC schema (implied, + because there is no formal schema which specifies the use of the + USMARC fields outside of ISO2709). The resultant, two-level record is + then mapped directly from the internal representation to ISO2709. See + the GILS schema definition files for a detailed example of this + approach. + + + + + + Explain. This representation is only available for records + belonging to the Explain schema. + + + + + + Summary. This ASN-1 based structure is only available for records + belonging to the Summary schema - or schema which provide a mapping + to this schema (see the description of the schema mapping facility + above). + + + + + + SOIF. Support for this syntax is experimental, and is currently + keyed to a private Index Data OID (1.2.840.10003.5.1000.81.2). All + abstract syntaxes can be mapped to the SOIF format, although nested + elements are represented by concatenation of the tag names at each + level. + + + + + + + + + diff --git a/doc/indexdata.xml b/doc/indexdata.xml index 7115d58..392de00 100644 --- a/doc/indexdata.xml +++ b/doc/indexdata.xml @@ -1,63 +1,58 @@ + -About Index Data and the Zebra Server - - -Index Data is a consulting and software-development enterprise that -specialises in library and information management systems. Our -interests and expertise span a broad range of related fields, and one -of our primary, long-term objectives is the development of a powerful -information management -system with open network interfaces and hypermedia capabilities. - - - -We make this software available free of charge for not-for-profit -purposes, as a service to the networking community, and to further -the development and use of quality software for open network -communication. - - - -If you like this software, and would like to use all or part of it in -a commercial product, or to provide a commercial database service, -please contact us to discuss the details. We'll be happy to answer -questions about the software, and about our services in general. If -you have specific requirements to the software, we'll be glad to offer -our advice - and if you need to adapt the software to a special -purpose, our consulting services and expert knowledge of the software -is available to you at favorable rates. - - - - - -Index Data -Ryesgade 3 -DK-2200 Copenhagen N - - - - - - - -Phone: +45 3536 3672 -Fax : +45 3536 0449 -Email: info@indexdata.dk - - - - - -The Random House College Dictionary, 1975 edition -offers this definition of the -word "Zebra": - - - -Zebra, n., any of several horselike, African mammals of the genus Equus, -having a characteristic pattern of black or dark-brown stripes on -a whitish background. - - + About Index Data and the Zebra Server + + + Index Data is a consulting and software-development enterprise that + specializes in library and information management systems. Our + interests and expertise span a broad range of related fields, and one + of our primary, long-term objectives is the development of a powerful + information management + system with open network interfaces and hyper-media capabilities. + + We make this software available free of charge, on a fairly unrestrictive + license; as a service to the networking community, and to further the + development of quality software for open network communication. + + We'll be happy to answer questions about the software, and about ourselves + in general. + + +
+ Index Data Aps + Købmagergade 43 + 1150 Copenhagen K + Denmark + Phone +45 3341 0100 + Fax +45 3341 0101 + Email info@indexdata.dk +
+ + + The Random House College Dictionary, 1975 edition + offers this definition of the + word "Zebra": + + + + + Zebra, n., any of several horselike, African mammals of the genus Equus, + having a characteristic pattern of black or dark-brown stripes on + a whitish background. + + + diff --git a/doc/installation.xml b/doc/installation.xml index 14ec6a0..0809bf7 100644 --- a/doc/installation.xml +++ b/doc/installation.xml @@ -1,79 +1,86 @@ + Installation + + An ANSI C compiler is required to compile the Zebra + server system — gcc works fine if your + own system doesn't provide an adequate compiler. + + + + Unpack the distribution archive. The configure + shell script attempts to guess correct values for various + system-dependent variables used during compilation. + It uses those values to create a 'Makefile' in each directory of Zebra. + + + + To run the configure script type: -Installation - - -An ANSI C compiler is required to compile the Zebra -server system — gcc works fine if your own system doesn't -provide an adequate compiler. - - - -Unpack the distribution archive. The configure shell script -attempts to guess correct values for various system-dependent variables -used during compilation. It uses those values to create a 'Makefile' in -each directory of Zebra. - - - -To run the configure script type: - - + ./configure - - - + - -The configure script attempts to use C compiler specified by -the CC environment variable. If not set, cc -will be used. The CFLAGS environment variable holds -options to be passed to the C compiler. If you're using a Bourne-shell -compatible shell you may pass something like this: - - + + + + The configure script attempts to use C compiler specified by + the CC environment variable. + If not set, cc or GNU C will be used. + The CFLAGS environment variable holds + options to be passed to the C compiler. If you're using a + Bourne-shell compatible shell you may pass something like this: + + CC=/opt/ccs/bin/cc CFLAGS=-O ./configure - + - - - -When configured build the software by typing: - - + + + + When configured build the software by typing: + + make - + + + + + + If successful, two executables have been created in the sub-directory + index. + + + + zebrasrv + + + The Z39.50 server and search engine. + + + + + zebraidx + + + The administrative indexing tool. + + + + + - - - -As an option you may type make depend to create -source file dependencies for the package. This is only needed, -however, if you alter the source. - - - -If successful, two executables have been created in the sub-directory -index. - - - -zebrasrv - - -The Z39.50 server and search engine. - - - - -zebraidx - - -The administrative tool for the search index. - - - - - - + diff --git a/doc/introduction.xml b/doc/introduction.xml index 1fbb3aa..0f39ec9 100644 --- a/doc/introduction.xml +++ b/doc/introduction.xml @@ -1,293 +1,294 @@ -Introduction - - -Overview - - -The Zebra system is a fielded free-text indexing and retrieval engine with a -Z39.50 frontend. You can use any commercial or freeware Z39.50 client -to access data stored in Zebra. - - - -The Zebra server is our first step towards the development of a fully -configurable, open information system. Eventually, it will be paired -off with a powerful Z39.50 client to support complex information -management tasks within almost any application domain. We're making -the server available now because it's no fun to be in the open -information retrieval business all by yourself. We want to allow -people with interesting data to make their things -available in interesting ways, without having to start out -by implementing yet another protocol stack from scratch. - - - -This document is an introduction to the Zebra system. It will tell you -how to compile the software, and how to prepare your first database. -It also explains how the server can be configured to give you the -functionality that you need. - - - -If you find the software interesting, you should join the support -mailing-list by sending email to zebra-request@indexdata.dk. - - - - - -Features - - -This is a list of some of the most important features of the -system. - - - - - - - - -Supports updating - records can be added and deleted without -rebuilding the index from scratch. -The update procedure is tolerant to crashes or hard interrupts -during register updating - registers can be reconstructed following a crash. -Registers can be safely updated even while users are accessing the server. - - - - - - -Supports large databases - files for indices, etc. can be -automatically partitioned over multiple disks. - - - - - - -Supports arbitrarily complex records - base input format is an -SGML-like syntax which allows nested (structured) data elements, as -well as variant forms of data. - - - - - - -Supports random storage formats. A system of input filters driven by -regular expressions allows you to easily process most ASCII-based -data formats. SGML, ISO2709 (MARC), and raw text are also supported. - - - - - - -Supports boolean queries as well as relevance-ranking (free-text) -searching. Right truncation and masking in terms are supported, as -well as full regular expressions. - - - - - - -Supports multiple concrete syntaxes -for record exchange (depending on the configuration): GRS-1, SUTRS, -ISO2709 (*MARC). Records can be mapped between record syntaxes and -schema on the fly. - - - - - - -Supports approximate matching in registers (ie. spelling mistakes, -etc). - - - - - - - - - -Protocol support: - - - - - - - - -Protocol facilities: Init, Search, Retrieve, Browse and Sort. - - - - - - -Piggy-backed presents are honored in the search-request. - - - - - - -Named result sets are supported. - - - - - - -Easily configured to support different application profiles, with -tables for attribute sets, tag sets, and abstract syntaxes. -Additional tables control facilities such as element mappings to -different schema (eg., GILS-to-USMARC). - - - - - - -Complex composition specifications using Espec-1 are partially -supported (simple element requests only). - - - - - - -Element Set Names are defined using the Espec-1 capability of the -system, and are given in configuration files as simple element -requests (and possibly variant requests). - - - - - - -Some variant support (not fully implemented yet). - - - - - - -Using the YAZ toolkit for the protocol implementation, the -server can utilise a plug-in XTI/mOSI implementation (not included) to -provide SR services over an OSI stack, as well as Z39.50 over TCP/IP. - - - - - - -Zebra runs on most Unix-like systems as well as Windows NT - a binary -distribution for Windows NT is forthcoming - so far, the installation -requires MSVC++ to compile the system (we use version 5.0). - - - - - - - - - - - -Future Work - - -This is a beta-release of the software, to allow you to look at -it - try it out, and assess whether it can be of use to you. - - - -These are some of the plans that we have for the software in the near -and far future, approximately ordered after their relative importance. -Items marked with an -asterisk will be implemented before the -last beta release. - - - - - - - - -*Complete the support for variants. - - - - - - -*Finalize the data element include facility -to support multimedia data elements in records. - - - - - - -Add more sophisticated relevance ranking mechanisms. Add support for soundex -and stemming. Add relevance feedback support. - - - - - - -Complete EXPLAIN support. - - - - - - -Add support for very large records by implementing segmentation and/or -variant pieces. - - - - - - -Support the Item Update extended service of the protocol. - - - - - - -We want to add a management system that allows you to -control your databases and configuration tables from a graphical -interface. We'll probably use Tcl/Tk to stay platform-independent. - - - - - - - - - -Programmers thrive on user feedback. If you are interested in a facility that -you don't see mentioned here, or if there's something you think we -could do better, please drop us a mail. If you think it's all really -neat, you're welcome to drop us a line saying that, too. You'll find -contact info at the end of this file. - - - + Introduction + + + Overview + + + The Zebra system is a fielded free-text indexing and retrieval engine with a + Z39.50 frontend. You can use any commercial or freeware Z39.50 client + to access data stored in Zebra. + + + + The Zebra server is our first step towards the development of a fully + configurable, open information system. Eventually, it will be paired + off with a powerful Z39.50 client to support complex information + management tasks within almost any application domain. We're making + the server available now because it's no fun to be in the open + information retrieval business all by yourself. We want to allow + people with interesting data to make their things + available in interesting ways, without having to start out + by implementing yet another protocol stack from scratch. + + + + This document is an introduction to the Zebra system. It will tell you + how to compile the software, and how to prepare your first database. + It also explains how the server can be configured to give you the + functionality that you need. + + + + If you find the software interesting, you should join the support + mailing-list by sending email to + zebra-request@indexdata.dk. + + + + + + Features + + + This is a list of some of the most important features of the + system. + + + + + + + + + Supports updating - records can be added and deleted without + rebuilding the index from scratch. + The update procedure is tolerant to crashes or hard interrupts + during register updating - registers can be reconstructed following + a crash. + Registers can be safely updated even while users are accessing + the server. + + + + + + Supports large databases - files for indices, etc. can be + automatically partitioned over multiple disks. + + + + + + + Supports arbitrarily complex records - base input format is an + SGML-like syntax which allows nested (structured) data elements, as + well as variant forms of data. + + + + + + + Supports random storage formats. A system of input filters driven by + regular expressions allows you to easily process most ASCII-based + data formats. SGML, ISO2709 (MARC), and raw text are also supported. + + + + + + + Supports boolean queries as well as relevance-ranking (free-text) + searching. Right truncation and masking in terms are supported, as + well as full regular expressions. + + + + + + + Supports multiple concrete syntaxes + for record exchange (depending on the configuration): GRS-1, SUTRS, + ISO2709 (*MARC). Records can be mapped between record syntaxes and + schema on the fly. + + + + + + + Supports approximate matching in registers (ie. spelling mistakes, + etc). + + + + + + + + + + Protocol support: + + + + + + + + + Protocol facilities: Init, Search, Retrieve, Browse and Sort. + + + + + + + Piggy-backed presents are honored in the search-request. + + + + + + + Named result sets are supported. + + + + + + + Easily configured to support different application profiles, with + tables for attribute sets, tag sets, and abstract syntaxes. + Additional tables control facilities such as element mappings to + different schema (eg., GILS-to-USMARC). + + + + + + + Complex composition specifications using Espec-1 are partially + supported (simple element requests only). + + + + + + + Element Set Names are defined using the Espec-1 capability of the + system, and are given in configuration files as simple element + requests (and possibly variant requests). + + + + + + + Some variant support (not fully implemented yet). + + + + + + + Using the YAZ toolkit for the protocol implementation, the + server can utilise a plug-in XTI/mOSI implementation (not included) to + provide SR services over an OSI stack, as well as Z39.50 over TCP/IP. + + + + + + + Zebra runs on most Unix-like systems as well as Windows NT - a binary + distribution for Windows NT is forthcoming - so far, the installation + requires MSVC++ to compile the system (we use version 5.0). + + + + + + + + + + + + Future Work + + + These are some of the plans that we have for the software in the near + and far future, approximately ordered after their relative importance. + Items marked with an + asterisk will be implemented before the + last beta release. + + + + + + + *Complete the support for variants. + + + + + + *Finalize the data element include facility + to support multimedia data elements in records. + + + + + + Add more sophisticated relevance ranking mechanisms. + Add support for soundex and stemming. + Add relevance feedback support. + + + + + + Complete EXPLAIN support. + + + + + + Add support for very large records by implementing segmentation and/or + variant pieces. + + + + + + Support the Item Update extended service of the protocol. + + + + + + We want to add a management system that allows you to + control your databases and configuration tables from a graphical + interface. + + + + + + + Programmers thrive on user feedback. If you are interested in a + facility that you don't see mentioned here, or if there's something + you think we could do better, please drop us a mail. + If you think it's all really neat, you're welcome to drop us a line + saying that, too. You'll find contact info at the end of this file. + + + + diff --git a/doc/license.xml b/doc/license.xml index 07002b0..90aa59c 100644 --- a/doc/license.xml +++ b/doc/license.xml @@ -52,3 +52,17 @@ OF THIS SOFTWARE. + diff --git a/doc/zebra.xml.in b/doc/zebra.xml.in index de17c81..5ba825f 100644 --- a/doc/zebra.xml.in +++ b/doc/zebra.xml.in @@ -14,8 +14,13 @@ SebastianHammer + +AdamDickmeiss + 1995-2002 +Index Data + @@ -30,7 +35,6 @@ services with the software. This manual covers version @VERSION@ of Zebra. - &chap-introduction; diff --git a/doc/zebraphp.dsl.in b/doc/zebraphp.dsl.in new file mode 100644 index 0000000..a6ca884 --- /dev/null +++ b/doc/zebraphp.dsl.in @@ -0,0 +1,98 @@ + +]> + + + + + +(define %use-id-as-filename% #t) +(define %output-dir% "php") +(define %html-ext% ".php") +(define %shade-verbatim% #t) + +(define newline "\U-000D") + +(define (html-document title-sosofo body-sosofo) + (let* (;; Let's look these up once, so that we can avoid calculating + ;; them over and over again. + (prev (prev-chunk-element)) + (next (next-chunk-element)) + (prevm (prev-major-component-chunk-element)) + (nextm (next-major-component-chunk-element)) + (navlist (list prev next prevm nextm)) + + ;; Let's make it possible to control the output even in the + ;; nochunks case. Note: in the nochunks case, (chunk?) will + ;; return #t for only the root element. + (make-entity? (and (or (not nochunks) rootchunk) + (chunk?))) + + (make-head? (or make-entity? + (and nochunks + (node-list=? (current-node) + (sgml-root-element))))) + (doc-sosofo + (if make-head? + (make sequence + (make formatting-instruction data: + (string-append "<" "?php " + newline + "require \"../../id_common.inc\";" + newline + "id_header(\"" + ) + ) + title-sosofo + (make formatting-instruction data: + (string-append "\");" + newline + "?" ">" + ) + ) + (header-navigation (current-node) navlist) + body-sosofo + (footer-navigation (current-node) navlist) + (make formatting-instruction data: + (string-append "<" "?php id_footer() ?>") + ) + ) + body-sosofo + ) + ) + ) + (if make-entity? + (make entity + system-id: (html-entity-file (html-file)) + (if %html-pubid% + (make document-type + name: "HTML" + public-id: %html-pubid%) + (empty-sosofo)) + doc-sosofo) + (if (node-list=? (current-node) (sgml-root-element)) + (make sequence + (if %html-pubid% + (make document-type + name: "HTML" + public-id: %html-pubid%) + (empty-sosofo)) + doc-sosofo) + doc-sosofo) + ) + ) + ) + + + + + + +