Re: transaction ID query

On Thursday 30 August 2007 07:12:48 Alvaro Herrera wrote:
> Kevin Kempter wrote:
> > Hi List;
> >
> > can I run queries to see the following for postgres v 8.1.4:
>
> Update to 8.1.9 *soon* unless you want to be victim of a nasty autovac
> bug. And in case you already were (which you won't know until your
> database starts causing you hard-to-fix headaches), I suggest you
> connect to template0 and run VACUUM FREEZE for precaution.
>
> > a) where the db is per used transaction ID's (want to avoid a transaction
> > ID wrap-around scenario)
>
> select age(datfrozenxid) from pg_database;
>
> > b) a list of tables in the db and the last time they were vacuumed
>
> Examine the pg_stat views, though I am not sure if the vacuum columns
> were already in 8.1. In any case, in 8.1 Xid wraparound is tracked
> per-database, so you need database-wide vacuums. In 8.2 it is per table
> so it is easier to keep up tokempt date.

I've run a vacuum verbose on the entire database (actually on all db's within
the cluster) but now I still see large numbers for the following query. Am I
missing something? Are these db's still in danger of a tx ID wrap-around
failure?

ems-1=# select datname, age(datfrozenxid) from pg_database;
datname | age
-------------+------------
postgres | 1083972950
rbc | 1083972554
emsam-1-old | 1085384465
template1 | 1083966365
template0 | 1195263818
ems-1 | 1086979868

Thanks in advance...

/Kevin