Re: [GENERAL] Concurrency problem building indexes

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Wes <wespvp(at)syntegra(dot)com>
Cc: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: [GENERAL] Concurrency problem building indexes
Date: 2006-04-25 04:02:56
Message-ID: 9505.1145937776@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general pgsql-hackers

Wes <wespvp(at)syntegra(dot)com> writes:
> I can duplicate the error at will.

[ shrug... ] Worksforme.

There is a short interval at the end of the first CREATE INDEX on the
table where the problem would happen if another CREATE INDEX tries to
modify the pg_class row before the first one's committed. That would be
hard to hit with any regularity though. Subsequent CREATE INDEXes after
that should be completely reliable. If you are modifying the table
while it's being indexed, then the same small window would apply for
each CREATE INDEX not just the first ... but you didn't admit to that.

Care to put together a self-contained test case?

regards, tom lane

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Jaime Casanova 2006-04-25 04:16:03 Re: isnumeric - checking if text variable is convertable to numeric
Previous Message Wes 2006-04-25 03:39:44 Re: [GENERAL] Concurrency problem building indexes

Browse pgsql-hackers by date

  From Date Subject
Next Message Jim C. Nasby 2006-04-25 05:00:18 Re: Google SoC--Idea Request
Previous Message Wes 2006-04-25 03:39:44 Re: [GENERAL] Concurrency problem building indexes