Re: getting status transaction error

Merlin Moncure wrote:
> On 2/6/07, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
> >around 6:30 this morning, I started getting the following messages in my
> >log:
> >
> >Feb 6 06:33:34 mojo postgres[1117]: [2-1] :: ERROR: could not access
> >status of transaction 544441911
> >Feb 6 06:34:35 mojo postgres[1128]: [2-1] :: ERROR: could not access
> >status of transaction 544441911
> >[...]
> >
> >repeated roughly once a minute. I've never seen this before. this is
> >on postgres 8.1.1 running on fedora core 4 smp. I don't have any
> >contextual information yet but I'm getting ready to turn statement
> >logging on.
> >
> >Anybody know what this is?
> [x-posting to -hackers]
>
> actually, here is some more relevant bits from the log.
> Feb 6 06:31:33 mojo postgres[1088]: [1-1] :: LOG: autovacuum:
> processing database "template0"
> Feb 6 06:31:33 mojo postgres[1088]: [2-1] :: ERROR: could not access
> status of transaction 544441911
> Feb 6 06:31:33 mojo postgres[1088]: [2-2] :: DETAIL: could not open
> file "pg_clog/0207": No such file or directory

I guess the problem here is that autovacuum believes that template0
needs a database-wide vacuum due to Xid wraparound getting closer. And
that database seems to have Xid 544441911 somewhere, the clog bit for
which was in the 0207 file which was deleted some time ago.

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.