Re: Disabled features on Hot Standby - Mailing list pgsql-hackers

From Noah Misch
Subject Re: Disabled features on Hot Standby
Date
Msg-id 20120114111719.GA1081@tornado.leadboat.com
Whole thread Raw
In response to Re: Disabled features on Hot Standby  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Disabled features on Hot Standby  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
On Sat, Jan 14, 2012 at 08:08:29AM +0000, Simon Riggs wrote:
> On Sat, Jan 14, 2012 at 1:02 AM, Noah Misch <noah@leadboat.com> wrote:
> > However, CLUSTER/VACUUM FULL already
> > remove tuples still-visible to standby snapshots without provoking a recovery
> > conflict. ?(Again only with hot_standby_feedback=off.)
> 
> If that were the case it would be a bug.
> 
> CLUSTER/VACUUM FULL emit an AccessExclusiveLock record that would
> conflict with any current lock holders, so should be fine on that.

I speak of this sequence (M = master connection, S = standby connection):

M: CREATE TABLE t AS SELECT * FROM generate_series(1,1000) t(n);
S: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT 0;
M: DELETE FROM t WHERE n <= 10;
M: VACUUM FULL t;
S: SELECT count(*) FROM t; -- 990, should be 1000


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