On Jun 21, 2008, at 8:47 AM, hjeancha@freesurf.fr wrote:
> i use postgresql version7.4.7 on i386-pc-linux-gnu, autovacuum is
> configured to run on this database.
> But recently, we lost data for a database, we were able to connect
> the database but we couldn't see any table anymore.
> I suspected a transaction ID wraparound, and to fix it, i just
> imported data from a dump file.
> I tried to execute the following query:
> SELECT datname, age(datfrozenxid) FROM pg_database where age
> (datfrozenxid)<0;
> template1=# SELECT datname, age(datfrozenxid) FROM pg_database
> where age(datfrozenxid)<0;
> datname | age
> ------------------------------------------+-------------
> template0 | -597653514
> ez_info1 | -205024652
> XtDB | -205024658
>
>
> Does the negative value of age means that a transaction ID
> wraparound has already occured?
That would be my guess.
> Doing a manual vacuumdb on each database raise an error message
> saying:
> vacuumdb: vacuuming of database "ez_info1" failed: ERREUR: not
> enough stack items
That's probably a bug in vacuum, but even so, you'll want to re-
initdb if you want to just pull back in from a pg_dump.
If you can take the downtime to do a pg_dump/restore, you should
really upgrade to a more recent version. You'll get integrated
autovacuum and code that makes wraparound impossible. I would not
expect you to have any major code issues going to 8.0 or 8.1. Of
course going to 8.3 would be better, but you could run into some
compatibility issues. You'll get a performance gain to boot.
--
Decibel!, aka Jim C. Nasby, Database Architect decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828
