On Sat, 2006-11-04 at 12:35 -0500, Tom Lane wrote:
I wrote:
It's usually going to be the case that the oldest datvacuumxid is
template0's, meaning that it will never be possible to truncate clog
until autovacuum decides that template0 is at risk of wraparound and
goes and vacuums it.
Tom Lane wrote:
* It might seem that there's no point in per-table adjustment of
critical_age, since only the system-wide maximum means anything for
resource consumption. I'm not so sure though --- for a really large
table, the time needed to finish vacuuming it could be significant,
meaning
Simon Riggs [EMAIL PROTECTED] writes:
now we have agreed to have only 4 eras, IIRC:
1. In Progress Transactions 0 - OldestXmin
limit is OldestXmin
2. Completed, normal Xids, status in clog
limit is Freeze distance?
3. Frozen Xids, tuples frozen early
Heikki Linnakangas [EMAIL PROTECTED] writes:
I think a global critical_age parameter is just fine. If you have one
huge table that takes a long time to vacuum, just adjust critical_age so
that there's enough time for the huge table vacuum to finish before
wrap-around. That means that other
I wrote:
Simon Riggs [EMAIL PROTECTED] writes:
Perhaps you could edit the above if needed?
Xids older than freeze_distance will be frozen whenever
next visited by VACUUM, but there is no forcing function
until they exceed freeze_limit
In that case,
On Sun, 2006-11-05 at 12:01 -0500, Tom Lane wrote:
After re-reading the above, it strikes me that maybe names based around
freeze_min and freeze_max would be useful?
Works for me. They are clearly related, yet different and allow a
straightforward explanation of their need and use.
e.g.
Simon Riggs [EMAIL PROTECTED] writes:
On Sun, 2006-11-05 at 12:01 -0500, Tom Lane wrote:
After re-reading the above, it strikes me that maybe names based around
freeze_min and freeze_max would be useful?
Works for me. They are clearly related, yet different and allow a
straightforward
Simon Riggs [EMAIL PROTECTED] writes:
vacuum_freeze_min The latest TransactionId that will be frozen during
a VACUUM is calculated by CurrentTransactionId - vacuum_freeze_min.
vacuum_freeze_max
The maximum age, calculated as distance from CurrentTransactionId, that
will be allowed
