Re: Same query, same data different plan

> Ran analyze on both. Running the same query I'm getting different plans,
one x10 slower.

theory:

the "statistics target" is too low ?
THEN
different random sample --> different statistics ---> different plan,.

*"For large tables, ANALYZE takes a random sample of the table contents,
rather than examining every row. "*
https://www.postgresql.org/docs/current/sql-analyze.html

IMHO: Try to increase the statistics target (
"default_statistics_target" , .. )

regards,
Imre

Kostas Papadopoulos <kostas(at)methodosit(dot)com(dot)cy> ezt írta (időpont: 2022.
okt. 10., H, 14:56):

>
> I have two identical databases running in the same instance of Postgresql.
> Ran
> analyze on both. Running the same query I'm getting different plans, one
> x10 slower.
> Although I have solved my problem by re-writing the query, I want to
> understand why
> this is happening. If the configuration, Postgresql version, schema and
> data are the
> same, what other factors is the planner considering?
>
> --
>
> Kostas Papadopoulos
> KE MethodosIT
>
>
>
>