If an authority record is modified in any way, we trigger a merge to update all biblios using the authority. This also happens if we merge a duplciate authority into one that is in use, all biblios already attached to the correct authority are updated. If the heading or controlled indicators or thesaurus have changed, this makes sense, but if not, we are triggering many biblio modifications and reindexes that are not needed. We also need to consider the case where a See-From is is added and IncludeSeeFromInSearches is enabled
There is a development about adding URIs from 024 in auth to bib record when merging. A Biblibre report, forgot the number. This would be an exception.
Bug 22972
Created attachment 175665 [details] [review] Bug 34739: Linked biblios should not be merged (updated) when changes to an authority don't change the authorized heading Currently, the function C4::AuthoritiesMarc::merge calls ModBiblio for all bibliographic records linked to the modified authority record. It could seem a just behavior but we know that this could lead to performance problems. This is why AuthorityMergeLimit systempreference with merge_authorities.pl was introduced (earlier: dontmerge). Although this partially solves the performance problems, for moderately large and large catalogs (500+ K) and authority records linked with a large number of bibliographic records, performance problems still occur, even with overnight processing with merge_authorities.pl. This problem is particularly apparent when updating authority records from central databases, whose modifications are beyond our control. It turns out, however, that many such modifications to authority records involve fields other than the heading field (1XX in MARC 21), so these updates in fact do not modify bibliographic records. However, with the current merge function, every touch on an authority record forces a call to the ModBiblio function. The number of relatively expensive ModBiblio calls could be reduced by checking whether there has been an actual change in the field associated with the authority record. However, with IncludeSeeFromInSearches or IncludeSeeAlsoFromInSearches preferences enabled, the record should be refreshed in the search engine just in case (should the 4XX, 5XX fields have changed, which we don't know at this point). Test plan: ========== 1. Make sure to have CataloguingLog set to Log and IncludeSeeFromInSearches set to Include. 2. Have a bibliographic record with an authority record linked. Open the authority record in a separate tab, open it in the editor and save, without modifying it. Repeat this 2-3 times. In the bibliographic record tab open the Modification log and see a number of entries - for each “empty” modification of the linked authority record. 3. Apply the patch ; restart_all. 4. Repat p. 2. Note that there are no new entries in the log. 5. Edit the authority record again, this time putting in one of the proper 4XX $a subfield an uncommon word (but do not touch the 1XX field). Save the authority record. In the bibliographic record tab control that there are no new entries in the modification log. Make a search for the word put in 4XX field. You should get the bibliographic record(s) linked to the edited authority record, even though the bibliographic record itself has not been modified. 6. Edit the authority record again, this time changing the 1XX field. Save the authority record. In the bibliographic record tab control that there are is new entry in the modification log. Sponsored-by: Ignatianum University in Cracow
Created attachment 175666 [details] [review] Bug 34739: Unit tests BTW, there is a tiny adjustment to one of the previous subtests to fit to the modified merge behaviour.
*** Bug 38742 has been marked as a duplicate of this bug. ***
Created attachment 175667 [details] [review] Bug 34739: Linked biblios should not be merged (updated) when changes to an authority don't change the authorized heading Currently, the function C4::AuthoritiesMarc::merge calls ModBiblio for all bibliographic records linked to the modified authority record. It could seem a just behavior but we know that this could lead to performance problems. This is why AuthorityMergeLimit systempreference with merge_authorities.pl was introduced (earlier: dontmerge). Although this partially solves the performance problems, for moderately large and large catalogs (500+ K) and authority records linked with a large number of bibliographic records, performance problems still occur, even with overnight processing with merge_authorities.pl. This problem is particularly apparent when updating authority records from central databases, whose modifications are beyond our control. It turns out, however, that many such modifications to authority records involve fields other than the heading field (1XX in MARC 21), so these updates in fact do not modify bibliographic records. However, with the current merge function, every touch on an authority record forces a call to the ModBiblio function. The number of relatively expensive ModBiblio calls could be reduced by checking whether there has been an actual change in the field associated with the authority record. However, with IncludeSeeFromInSearches or IncludeSeeAlsoFromInSearches preferences enabled, the record should be refreshed in the search engine just in case (should the 4XX, 5XX fields have changed, which we don't know at this point). Test plan: ========== 1. Make sure to have CataloguingLog set to Log and IncludeSeeFromInSearches set to Include. 2. Have a bibliographic record with an authority record linked. Open the authority record in a separate tab, open it in the editor and save, without modifying it. Repeat this 2-3 times. In the bibliographic record tab open the Modification log and see a number of entries - for each “empty” modification of the linked authority record. 3. Apply the patch ; restart_all. 4. Repat p. 2. Note that there are no new entries in the log. 5. Edit the authority record again, this time putting in one of the proper 4XX $a subfield an uncommon word (but do not touch the 1XX field). Save the authority record. In the bibliographic record tab control that there are no new entries in the modification log. Make a search for the word put in 4XX field. You should get the bibliographic record(s) linked to the edited authority record, even though the bibliographic record itself has not been modified. 6. Edit the authority record again, this time changing the 1XX field. Save the authority record. In the bibliographic record tab control that there are is new entry in the modification log. Sponsored-by: Ignatianum University in Cracow Signed-off-by: Roman Dolny <roman.dolny@jezuici.pl>
Created attachment 175668 [details] [review] Bug 34739: Unit tests BTW, there is a tiny adjustment to one of the previous subtests to fit to the modified merge behaviour. Signed-off-by: Roman Dolny <roman.dolny@jezuici.pl>