Re: pg_dumpall failure - could not access status of transaction

Robert Leftwich wrote:
> pg_dump: Error message from server: ERROR: could not access status
> of transaction 3183024
> DETAIL: could not open file "pg_clog/0003": No such file or
> directory

If your database system has already experienced on the order of 3183024
transactions, then you should wonder where that file went. Otherwise
you probably have garbage on disk, pointing to a transaction that
hasn't happened yet. This is usually hardware trouble in any case,
unless you have actually deleted the file manually.

The alternative is that your database system has already seen more than
2^32 transactions and you have hit some bug in the transaction
wraparound, but that would be much less likely than the above cases.

> I'm (obviously) lost here - what is the correct way to track down the
> appropriate file and record to point pg_filedump at to view any
> corruption?

Look for something that contains 3183024 as a four-byte integer.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/