Tom Lane wrote:
ITAGAKI Takahiro <[EMAIL PROTECTED]> writes:
This is a stand-alone patch for aggressive freezing. I'll propose
to use OldestXmin instead of FreezeLimit as the freeze threshold
in the circumstances below:
I think it's a really bad idea to freeze that aggressively under any
circumstances except being told to (ie, VACUUM FREEZE). When you
freeze, you lose history information that might be needed later --- for
forensic purposes if nothing else. You need to show a fairly amazing
performance gain to justify that, and I don't think you can.
There could be a GUC vacuum_freeze_limit, and the actual FreezeLimit
would be calculated as
GetOldestXmin() - vacuum_freeze_limit
The default for vacuum_freeze_limit would be MaxTransactionId/2, just
as it is now.
greetings, Florian Pflug
---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster
