Re: In progress INSERT wrecks plans on table

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On 3 May 2013 13:41, Simon Riggs <simon@xxxxxxxxxxxxxxx> wrote:

> (3) to make the check on TransactionIdIsInProgress() into a heuristic,
> since we don't *need* to check that, so if we keep checking the same
> xid repeatedly we can reduce the number of checks or avoid xids that
> seem to be long running. That's slightly more coding than my quick
> hack here but seems worth it.
>
> I think we need both (1) and (3) but the attached patch does just (1).
>
> This is a similar optimisation to the one I introduced for
> TransactionIdIsKnownCompleted(), except this applies to repeated
> checking of as yet-incomplete xids, and to bulk concurrent
> transactions.

ISTM we can improve performance of TransactionIdIsInProgress() by
caching the procno of our last xid.

Mark, could you retest with both these patches? Thanks.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Attachment: cache_TransactionIdInProgress.v1.patch
Description: Binary data

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