Re: [HACKERS] Index corruption with CREATE INDEX CONCURRENTLY

Pavan Deolasee wrote:

> I can reproduce this entire scenario using gdb sessions. This also explains
> why the patch I sent earlier helps to solve the problem.

Ouch.  Great detective work there.

I think it's quite possible that this bug explains some index errors,
such as primary keys (or unique indexes) that when recreated fail with
duplicate values: the first value inserted would get in via an UPDATE
during the CIC race window, and sometime later the second value is
inserted correctly.  Because the first one is missing from the index,
the second one does not give rise to a dupe error upon insertion, but
they are of course both detected when the index is recreated.

I'm going to study the bug a bit more, and put in some patch before the
upcoming minor tag on Monday.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services