Horton

Re: Latest version of Hot Standby patch

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

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From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2009-01-07T21:56:02Z
Lists: pgsql-hackers 
Simon Riggs wrote:
> On Wed, 2009-01-07 at 15:43 +0200, Heikki Linnakangas wrote:
>> When there's no xids in the procarray, couldn't we just use 
>> latestCompletedXid instead of calling ReadNewTransactionId()?
> 
> latestCompletedXid is protected by ProcArrayLock so not much difference
> between those two.

The big difference is that we're already holding ProcArrayLock. You 
could read the value of latestCompletedXid before releasing 
ProcArrayLock, and wouldn't need the retry logic.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com