Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-20 Thread Christopher Browne
I just ran into a new little anomaly in pg_autovacuum... Note the interesting _negative_ numbers. Apparently something's rolling over. I have no _grand_ problem with what happened, namely "immediately checking again," as the system in question was doing heavy offline updates. But this is likely

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Rod Taylor
> So, pg_autovacuum does deal with them separately, but doesn't make an > effort to spread out the vacuums if all / multiple databases happen to > need it at the same time. > > In practice, I don't see this as a big problem right now, but it should > still be handled better by pg_autovacuum. I un

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Matthew T. O'Connor
On Thu, 2003-10-16 at 10:16, Rod Taylor wrote: > > The vacuum man page says, "FREEZE is not recommnded for routine use". > > That was enough to keep me away. However if vacuum freeze was > > considerably lighter than normal database wide vacuums then there might > > be an advantage to using it.

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Rod Taylor
> The vacuum man page says, "FREEZE is not recommnded for routine use". > That was enough to keep me away. However if vacuum freeze was > considerably lighter than normal database wide vacuums then there might > be an advantage to using it. Especially since when pg_autovaccum > decides it's tim

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Tom Lane
"Matthew T. O'Connor" <[EMAIL PROTECTED]> writes: > The vacuum man page says, "FREEZE is not recommnded for routine use". > That was enough to keep me away. However if vacuum freeze was > considerably lighter than normal database wide vacuums then there might > be an advantage to using it. If an

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Matthew T. O'Connor
On Thu, 2003-10-16 at 01:34, Christopher Kings-Lynne wrote: > Hi, > > Was just wondering if pg_autovacuum watches transaction ids and issues a > vacuum freeze before they roll over? Yes pg_autovacuum monitors for xid wraparound, when it sees that you are getting close, then it issues a database

Re: [HACKERS] pg_autovacuum and VACUUM FREEZE

2003-10-16 Thread Christopher Browne
In an attempt to throw the authorities off his trail, [EMAIL PROTECTED] (Christopher Kings-Lynne) transmitted: > Was just wondering if pg_autovacuum watches transaction ids and issues > a vacuum freeze before they roll over? > > If not, is it hard to do? It doesn't do a VACUUM FREEZE; it just doe