Re: running ANALYZE results in => duplicate key value violates unique constraint "pg_statistic_relid_att_inh_index"

On Wed, 2023-09-06 at 09:46 +0200, Torsten Krah wrote:
> I am running that one (official docker image)
>
> PostgreSQL 13.11 (Debian 13.11-1.pgdg110+1) on x86_64-pc-linux-gnu,
> compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit
>
> and one of my nightly jobs reported that error yesterday when running
> an "ANALYZE":
>
> FEHLER: doppelter Schlüsselwert verletzt Unique-Constraint »pg_statistic_relid_att_inh_index«
>   Detail: Schlüssel »(starelid, staattnum, stainherit)=(2609, 4, f)« existiert bereits.
>
> which should translate to something like:
>
> ERROR:  duplicate key value violates unique constraint "pg_statistic_relid_att_inh_index"
> > DETAIL:  Key (starelid, staattnum, stainherit)=(2609, 4, f) already exists.
>
>
> Anyone an idea what's wrong?

Yes: the metadata table pg_statistic has data corruption.

> Maybe (not?) related but sometimes the analyze does fail with:
>
> ERROR: attempted to delete invisible tuple

That also looks like data corrupton, albeit different one.

> Both errors are only happening here and there - so I don't have a
> reproducer, but still I am curious what is wrong here with me running
> an "ANALYZE" after my data import.

To fix the "pg_statistic" error:

- take down time

- set "allow_system_mods = on"

- TRUNCATE pg_statistic;

- ANALYZE;

You are lucky that the corrupted table is one that holds data that can be rebuilt.

Yours,
Laurenz Albe