Re: 8.1 index corruption woes

Tom Lane wrote:
> Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> > Tom Lane wrote:
> >> Another point to keep in mind, if you are trying to analyze files
> >> belonging to a live database, is that what you can see in the filesystem
> >> may not be the "current" contents of every page. For typical access
> >> patterns it'd be unsurprising for the visible index pages to lag behind
> >> those of the heap, since they'd be "hotter" and tend to stay in shared
> >> buffers longer.
>
> > Hmm, I think the files come from a PITR slave that's not online. I'll
> > ask to be sure.
>
> 8.1 didn't have restartpoint code, and of course bgwriter isn't running;
> so I believe filesystem pages on a PITR slave could be arbitrarily far
> out of date if the corresponding shared buffer got touched regularly.
> Try doing the analysis on the master immediately after a CHECKPOINT
> command.

Okay.

I'll also check out tomorrow the LSN on the involved pages to see if
there's anything obviously bogus.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support