Proposed feature is to add capability for additional search target languages to be specified.
Currently, Evergreen only allows the language specified in MARC 008 position 35-37 to be the target of a language search.
There is no current mechanism to allow for additional languages to be included as search targets.
The proposed change would add a new table (metabib.language_filter e.g.). This new table would contain a tsvector datatype.
This tsvector would contain the languages associated with each bib record (tag 008 35-37 and selected 041 records).
Search code would be changed to join the metabib.language_filter table during the search query build.

These changes will allow an additional MARC tag (041) and subfields to be searched for language, beyond the standard tag 008 position 35-37.

This feature will allow staff to search for alternate languages, in addition to the primary language found in MARC 008 field position 35-37.
An additional table, metabib.language_filter, would be added. This table would include a tsvector, which contains a vector of languages associated with
a bib record. These languages could be searched by staff using the language pulldown, or the "item_lang" search line command. If no languages were
selected in the language pulldown, there would be no change to current search; the "default" language would be used in searching.

The following perl module would be modified:

• ./Open-ILS/src/perlmods/lib/OpenILS/Application/Storage/Driver/Pg/QueryParser.pm
  

Code would be added to include a join on the metabib:language_filter, so that the search languages would be included in the SQL search query.

A new table, metabib.language_filter, would be added to the schema. The columns of the table would be:

• id (primary key)
• source (foreign key to biblio.record_entry.id)
• value (tsvector containing 008 (35-37) and 041 subfield values containing languages associated with the selected bib record.

The language_filter table would be populated via a sql script, extracting 008 (35-37) and 041 subfields from the biblio.record_entry marc field.

A new trigger would be added:

• biblio.record_entry.language_filter_trigger

A new trigger procedure would be added for biblio.record_entry.language_filter_trigger:

• biblio.record_entry.update_language_filter

A new row would be added to config.org_unit_setting_type. This would allow the MARC 041 subfield(s) to be set via the Library Settings editor of Local Administration. The value in the org_unit_setting_type would be an array containing the specified subfield.