documention wrong or just not clear?

Started by Robert Treatabout 19 years ago2 messagesdocs
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#1Robert Treat
xzilla@users.sourceforge.net

In http://www.postgresql.org/docs/8.2/static/routine-vacuuming.html it says:

"The age column measures the number of transactions from the cutoff XID to the
current transaction's XID. Immediately after a VACUUM, age(relfrozenxid)
should be a little more than the vacuum_freeze_min_age setting that was used
(more by the number of transactions started since the VACUUM started). "

However my results don't seem to bear that out:

postgres=# show vacuum_freeze_min_age;
vacuum_freeze_min_age
-----------------------
100000000
(1 row)
postgres=# VACUUM ;
VACUUM
postgres=# select min (age(relfrozenxid)) from pg_class where relkind = 'r';
min
--------
253045
(1 row)

--
Robert Treat
Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Robert Treat (#1)
Re: documention wrong or just not clear?

Robert Treat <xzilla@users.sourceforge.net> writes:

In http://www.postgresql.org/docs/8.2/static/routine-vacuuming.html it says:
"The age column measures the number of transactions from the cutoff XID to the
current transaction's XID. Immediately after a VACUUM, age(relfrozenxid)
should be a little more than the vacuum_freeze_min_age setting that was used
(more by the number of transactions started since the VACUUM started). "

However my results don't seem to bear that out:

I would imagine that your database (or at least some of your tables) are
not yet vacuum_freeze_min_age transactions old.

regards, tom lane