Re: Unable to explain DB error - Mailing list pgsql-performance

From Tom Lane
Subject Re: Unable to explain DB error
Date
Msg-id 25774.1122574768@sss.pgh.pa.us
Whole thread Raw
In response to Unable to explain DB error  (Steven Rosenstein <srosenst@us.ibm.com>)
List pgsql-performance
Steven Rosenstein <srosenst@us.ibm.com> writes:
> Any idea why Postgres would be looking for a clog file name 0FC0 when the most recent filename is 04CE?

Corrupt data --- specifically a bad transaction number in a tuple
header.  (In practice, this is the first field looked at in which
we can readily detect an error, so you tend to see this symptom for
any serious data corruption situation.  The actual fault may well
be something like a corrupt page header causing the code to follow
"tuple pointers" that point to garbage.)

See the PG list archives for past discussions of dealing with corrupt
data.  pgsql-performance is pretty off-topic for this.

BTW, PG 7.4 and up handle this sort of thing much more gracefully ...
they can't resurrect corrupt data of course, but they tend not to
panic.

            regards, tom lane

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