Re: XID wraparound and busy databases - Mailing list pgsql-hackers

From Darcy Buskermolen
Subject Re: XID wraparound and busy databases
Date
Msg-id 200708151015.38162.darcy@dbitech.ca
Whole thread Raw
In response to Re: XID wraparound and busy databases  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Wednesday 15 August 2007 09:49:52 Tom Lane wrote:
> Heikki Linnakangas <heikki@enterprisedb.com> writes:
> > Maybe we can do something to reduce the xid consumption? For example,
> > reuse xids for read-only queries.
>
> Hmm, that's an idea.
>
> More simply, just keep the current transaction open (resetting
> everything but the XID) if we have made no changes by the time we're
> told to commit or rollback ... which is something we track already,
> so as not to waste cycles on useless commit XLOG records.

Jan and myself were discussing something like this as it would relate to a 
subscribe process for slony.

Jan care to summerize your thoughts on this?


>
> You'd want some upper limit on transaction lifetime, so as to avoid the
> "long lived transactions hurt VACUUM" problem, but even reusing a single
> xact for a few seconds would pretty much eliminate this issue, I bet.
> It's hard to see how anyone could be doing 6K xacts/sec unless most are
> read-only.
>
>             regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
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