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Re: Small locking bugs in hs

Simon Riggs <simon@2ndquadrant.com>

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From: Simon Riggs <simon@2ndQuadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, Robert Haas <robertmhaas@gmail.com>
Date: 2010-01-20T14:09:05Z
Lists: pgsql-hackers 
On Wed, 2010-01-20 at 14:13 +0100, Andres Freund wrote:
> I do understand it correctly that in CancelVirtualTransaction
> LW_SHARED is 
> taken only so that another transaction can finish during that time?

We're canceling one specific vxid, so no need to block other snapshots
from being taken.

Read only queries don't take ProcArrayLock when they complete and the
Startup process is the only process to record xact completion during
recovery.

-- 
 Simon Riggs           www.2ndQuadrant.com