Re: Postgres NOT IN vs NOT EXISTS optimization

On Tue, Jun 14, 2022 at 12:09:16PM -0400, Tom Lane wrote: > "Dirschel, Steve" writes: > > Is Postgres able to drive the query the same way with the NOT IN as the > > NOT EXISTS is doing or is that only available if the query has a NOT > > EXISTS? > > NOT IN is not optimized very well in PG, becau

Re: Postgres NOT IN vs NOT EXISTS optimization

"Dirschel, Steve" writes: > Is Postgres able to drive the query the same way with the NOT IN as the > NOT EXISTS is doing or is that only available if the query has a NOT > EXISTS? NOT IN is not optimized very well in PG, because of the strange semantics that the SQL spec demands when the sub-que

Re: Postgres NOT IN vs NOT EXISTS optimization

I think this explains the situation well: https://wiki.postgresql.org/wiki/Don't_Do_This#Don.27t_use_NOT_IN On Tue, Jun 14, 2022 at 11:59 AM Dirschel, Steve < steve.dirsc...@thomsonreuters.com> wrote: > We are in the process of migrating from Oracle to Postgres and the > following query does muc