Re: Postgres 15 SELECT query doesn't use index under RLS
От
Alexander Okulovich
Тема
Re: Postgres 15 SELECT query doesn't use index under RLS
Дата
Msg-id
3e30e681-1694-4636-b909-036fb5de6a20@stiltsoft.com
Ответ на
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Дерево обсуждения
Postgres 15 SELECT query doesn't use index under RLS Alexander Okulovich <aokulovich@stiltsoft.com>
Re: Postgres 15 SELECT query doesn't use index under RLS Tom Lane <tgl@sss.pgh.pa.us>
Re: Postgres 15 SELECT query doesn't use index under RLS Alexander Okulovich <aokulovich@stiltsoft.com>
Re: Postgres 15 SELECT query doesn't use index under RLS Tom Lane <tgl@sss.pgh.pa.us>
Re: Postgres 15 SELECT query doesn't use index under RLS Alexander Okulovich <aokulovich@stiltsoft.com>
Re: Postgres 15 SELECT query doesn't use index under RLS Tom Lane <tgl@sss.pgh.pa.us>
Re: Postgres 15 SELECT query doesn't use index under RLS Alexander Okulovich <aokulovich@stiltsoft.com>
Postgres Locking "Dirschel, Steve" <steve.dirschel@thomsonreuters.com>
Re: Postgres Locking Tom Lane <tgl@sss.pgh.pa.us>
Performance down with JDBC 42 "Abraham, Danny" <danny_abraham@bmc.com>
Performance problems with Postgres JDBC 42.4.2 Jose Osinde <jose.osinde@gmail.com>
Re: Performance problems with Postgres JDBC 42.4.2 Dave Cramer <davecramer@postgres.rocks>
Re: Performance down with JDBC 42 Laurenz Albe <laurenz.albe@cybertec.at>
RE: [EXTERNAL] Re: Performance down with JDBC 42 "Abraham, Danny" <danny_abraham@bmc.com>
Re: [EXTERNAL] Re: Performance down with JDBC 42 Andreas Kretschmer <andreas@a-kretschmer.de>
Re: [EXTERNAL] Re: Performance down with JDBC 42 Frits Hoogland <frits.hoogland@gmail.com>
Re: [EXTERNAL] Re: Performance down with JDBC 42 Jeff Janes <jeff.janes@gmail.com>
RE: [EXTERNAL] Re: Performance down with JDBC 42 "Abraham, Danny" <danny_abraham@bmc.com>
Re: [EXTERNAL] Re: Performance down with JDBC 42 David Rowley <dgrowleyml@gmail.com>
Re: [EXTERNAL] Performance down with JDBC 42 Frits Hoogland <frits.hoogland@gmail.com>
RE: [EXTERNAL] Performance down with JDBC 42 "Abraham, Danny" <danny_abraham@bmc.com>
RE: Postgres Locking "Smith, Travis" <Travis.Smith@circana.com>
Hi Tomek,
Unfortunately, I didn't dig into this. This request is recommended to provide when describing slow query issues, but looks like it relates to JOINs in the query, which we don't have.
Kind regards,
Alexander
On 19.10.2023 09:43, Tomek wrote:
Hi Alexander!Apart from the problem you are writing about I'd like to ask you to explain how you interpret counted frac_MCV - for me it has no sense at all to summarize most_common_freqs.Please rethink it and explain what was the idea of such SUM ? I understand that it can be some measure for ratio of NULL values but only in some cases when n_distinct is small.regardsStatistics: n_distinct, MCV, histogram
Useful to check statistics leading to bad join plan. SELECT (SELECT sum(x) FROM unnest(most_common_freqs) x) frac_MCV, tablename, attname, inherited, null_frac, n_distinct, array_length(most_common_vals,1) n_mcv, array_length(histogram_bounds,1) n_hist, correlation FROM pg_stats WHERE attname='...' AND tablename='...' ORDER BY 1 DESC;
Returns 0 rows.
Kind regards,
Alexander
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