Re: Transaction error

"Casey T. Deccio" <casey(at)deccio(dot)net> writes:
> On Thu, 2005-09-01 at 11:59 -0400, Tom Lane wrote:
>> Define "didn't work" ... what happened, exactly, when you tried it?

> Sorry, I was too tired last night to try it again and post the error.
> Here it is:

> ERROR: could not access status of transaction 4114057
> DETAIL: could not read from file "/var/lib/postgres/data/pg_clog/0003"
> at offset 237568: Success

Apparently your backup wasn't very current, and contains a version of
that clog file that hasn't yet reached full size. Oh well, I was hoping
you'd get valid data from the backup.

> How would I create a dummy clog segment file, if needed?

What you'll have to do is pad out the segment file to full size (256K)
by appending zeroes. (dd from /dev/zero is useful for this.)

Note that you will probably not get a completely consistent database out
of this --- there are going to be some transactions that appear
uncommitted or partially committed. I'd recommend a dump and reload to
help you revalidate your data, plus you'll have to apply any manual
consistency checks you can think of.

regards, tom lane