public inbox for [email protected]  

help / color / mirror / Atom feed

From: Олег Самойлов <[email protected]>
To: Pgsql-admin <[email protected]>
Subject: autoanalyze did not run
Date: Mon, 26 Jan 2026 08:31:24 +0300
Message-ID: <[email protected]> (raw)

Hi, all.

I try to investigate why autoanalyze did not run in time of our initial 
loading data. Yes, I know, running analyze manually is highly 
recommended in such case. But is must run automatically too. Or it us 
bugged?
Initial loading data made by COPY command. After this (and after all 
autovacuum) I see:

select c.relkind, count(*) from pg_stat_user_tables as s join pg_class 
as c on (s.relid=c.oid) where s.autoanalyze_count=0 and s.n_live_tup>0 
group by c.relkind;
-[ RECORD 1 ]-
relkind | r
count   | 1069

More investigation:

select relid::regclass, n_live_tup, n_tup_ins, n_tup_upd, 
n_mod_since_analyze from pg_stat_user_tables as s join pg_class as c on 
(s.relid=c.oid) where s.autoanalyze_count=0 and relkind='r' and 
n_live_tup>0 limit 1;
-[ RECORD 1 ]-------+----------
relid               | addresses
n_live_tup          | 13844405
n_tup_ins           | 0
n_tup_upd           | 0
n_mod_since_analyze | 0

select count(*) from addresses;
-[ RECORD 1 ]---
count | 13844347

This is example for only 1 table, but there are one thousand such. What 
is exact criteria to launch autoanalyze? On columns of 
pg_stat_user_tables it is based? If only on n_mod_since_analyze, there 
can be a logical trap (bug), analyze will have 
always n_mod_since_analyze=0 on tables where it never yet ran, so it 
will not run. Or may be there is an other reason?

I am afraid that this bug can be not only on initial loading, but in 
normal work too.


PostgreSQL 17.7 (Debian 17.7-3.pgdg13+1) on x86_64-pc-linux-gnu, 
compiled by gcc (Debian 14.2.0-19) 14.2.0, 64-bit (from PGDG)

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected]
  Subject: Re: autoanalyze did not run
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox