Re: Aggressive freezing in lazy-vacuum - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Aggressive freezing in lazy-vacuum
Date
Msg-id 18982.1173110551@sss.pgh.pa.us
Whole thread Raw
In response to Aggressive freezing in lazy-vacuum  (ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp>)
Responses Re: Aggressive freezing in lazy-vacuum
Re: Aggressive freezing in lazy-vacuum
List pgsql-hackers
ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp> 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.

            regards, tom lane

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