Re: New strategies for freezing, advancing relfrozenxid early - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: New strategies for freezing, advancing relfrozenxid early
Date
Msg-id CAH2-Wz=VAgHL6E92Mi-jaOt_40Fj-Q5YD7n5r6P3gftgE2vdCQ@mail.gmail.com
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In response to Re: New strategies for freezing, advancing relfrozenxid early  (Andres Freund <andres@anarazel.de>)
Responses Re: New strategies for freezing, advancing relfrozenxid early  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Wed, Jan 25, 2023 at 5:26 PM Andres Freund <andres@anarazel.de> wrote:
> Another bad scenario: Some longrunning / hung transaction caused us to get
> close to the xid wraparound. Problem was resolved, autovacuum runs. Previously
> we wouldn't have frozen the portion of the table that was actively changing,
> now we will. Consequence: We get closer to the "no write" limit / the outage
> lasts longer.

Obviously it isn't difficult to just invent a new rule that gets
applied by lazy_scan_strategy. For example, it would take me less than
5 minutes to write a patch that disables eager freezing when the
failsafe is in effect.

> I don't see an alternative to reverting this for now.

I want to see your test case before acting.

-- 
Peter Geoghegan



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