On 2018-Jul-23, Andres Freund wrote:
> Hi,
>
> On 2018-07-23 21:03:32 +0300, Mariel Cherkassky wrote:
> > Today I faced a situation where I saw a postgresql 9.2 database that had
> > duplicated rows in pg_autid. I saw 6 roles while 3 of them were duplicated
> > (3 uniques rolenames in total). I checked and the oid of the duplicates
> > were the same oid as the originals. The solution was running vacuum on the
> > table but I wanted to understand how this situation was created ? Why even
> > with unique index on the rolname I saw duplicated values for rolname ?
>
> That suggests some form of corruption. Which version of 9.2 did this
> occur on? Did you have any OS level crashes? Ran with fsync=off?
I have vague memories of seeing this recently. Can you please show
select xmin, xmax, ctid, oid, rolname from pg_authid
And the output of pg_controldata.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
