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
