I think you can improve it by doing a LEFT JOIN between the two tables instead of the IN comparison. That way you will find those without matching authorities when they auth_header counterpart is NULL. If you want to go precise, you should also add 100$9 vs authid to the game. Good luck! El sáb, 2 jul 2022 10:51, Doug Kingston <dpk@randomnotes.org> escribió:
Report: Authors not in Authorities
SELECT DISTINCT(author) AS heading FROM biblio WHERE author NOT IN (SELECT ExtractValue(marcxml,'//datafield[@tag="100"]/subfield[@code="a"]') AS heading FROM auth_header WHERE authtypecode='PERSO_NAME')ORDER BY heading
I am not a SQL expert, but I believe this is doing an unkeyed troll through every authority record for every biblio (O(Nbibs * Mauths), which is pretty bad). I suspect we can do better by trolling Auths once to create a set and then compare Bib authors against it. How can we do this?
-Doug- _______________________________________________ Koha-devel mailing list Koha-devel@lists.koha-community.org https://lists.koha-community.org/cgi-bin/mailman/listinfo/koha-devel website : https://www.koha-community.org/ git : https://git.koha-community.org/ bugs : https://bugs.koha-community.org/