Re: SnapshotResetXmin - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: SnapshotResetXmin
Date
Msg-id 20090116163714.GB12449@alvh.no-ip.org
Whole thread Raw
In response to SnapshotResetXmin  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: SnapshotResetXmin  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Simon Riggs wrote:
> 
> SnapshotResetXmin is called 3 times after each statement in
> ReadCommitted mode.
> 
> Too keen, perhaps?

It is called each time a snapshot is unregistered and each time an
active snapshot is popped.  I don't see any way to reduce the number of
calls without complicating the code a lot ... do you have any ideas?

Maybe we could check whether TransState is not TRANS_INPROGRESS and skip
it in those cases ...?

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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