Re: How to speed up product code and subcode match
Andrus <kobruleht2@hot.ee>
From: Andrus <kobruleht2@hot.ee>
To: Tom Lane <tgl@sss.pgh.pa.us>, "Bzm@g" <bzm@2bz.de>
Cc: pgsql-general <pgsql-general@postgresql.org>
Date: 2023-05-23T14:49:16Z
Lists: pgsql-general
Hi! Using index create index on toode ( *split_part( toode, '/',1) *) and query select toode.toode , n2, n3, n4 from toode, vordlusajuhinnak where *split_part( toode.toode, '/',1) *= vordlusajuhinnak.toode; reduces run time to 5 minutes. Andrus. 23.05.2023 17:26 Andrus kirjutas: > > Hi! > >> Separate >> the product code and size into two columns --- if there's somebody >> who really wants to see them in the above format, give them a >> view or generated column. Then instead of the impossible-to-optimize >> queries you showed, you could do something like >> >> select toode.toode , n2, n3, n4 >> from toode, vordlusajuhinnak >> where toode.toode = vordlusajuhinnak.toode; >> > Can function index > > create index on toode ( *split_part( toode, '/',1) *) > > and query > > select toode.toode , n2, n3, n4 > > from toode, vordlusajuhinnak > > where *split_part( toode.toode, '/',1) *= vordlusajuhinnak.toode; > > > used and keeping existing table structure? Functional index should > produce same speed improvement as using separate column? > > Andrus. > >