Re: [HACKERS] Re: pgsql: Avoid extra locks in GetSnapshotData if old_snapshot_threshold < - Mailing list pgsql-committers

From Andres Freund
Subject Re: [HACKERS] Re: pgsql: Avoid extra locks in GetSnapshotData if old_snapshot_threshold <
Date
Msg-id 20160507004844.wbze4nhjqa67io2a@alap3.anarazel.de
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In response to Re: [HACKERS] Re: pgsql: Avoid extra locks in GetSnapshotData if old_snapshot_threshold <  (Kevin Grittner <kgrittn@gmail.com>)
Responses Re: [HACKERS] Re: pgsql: Avoid extra locks in GetSnapshotData if old_snapshot_threshold <  (Kevin Grittner <kgrittn@gmail.com>)
List pgsql-committers
On 2016-05-06 19:43:24 -0500, Kevin Grittner wrote:
> It's disappointing that I am not getting more consistent numbers,
> but NUMA can be hard to manage that way.

FWIW, in my experience, unless you disable autovacuum (or rather
auto-analyze), the effects from non-predicable analyze runs with
long-running snapshots are worse.  I mean the numa effects suck, but in
r/w workload effects of analyze are often much worse.


That comment reminds me of a question I had: Did you consider the effect
of this patch on analyze? It uses a snapshot, and by memory you've not
built in a defense against analyze being cancelled.


> Will push shortly with the nit-pick fixes you requested.

Cool.

Greetings,

Andres Freund


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