Message-Id: <4D7F440A020000250003B8CD@gw.wicourts.gov>
Date: Tue, 15 Mar 2011 10:48:42 -0500
From: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>
To: <pgsql-admin@postgresql.org>,<gnanam@zoniac.com>
Subject: Re: PSQLException: ERROR: could not open relation
	 with	 OID xxxx
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	<4D7DEB6B020000250003B821@gw.wicourts.gov>
	<003601cbe2df$bf0c7480$3d255d80$@com>
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"Gnanakumar" <gnanam@zoniac.com> wrote:
 
>> If that doesn't do it I might try adding zero to numbers and
>> concatenating empty strings to try to prevent late use of the
>> OID.  (Essentially as a form of optimization barrier.)
> 
> I couldn't understand this approach clearly. Can you help explain
> me with some example?
 
For a string it would be changing something like this:
 
    schemaname,
 
to something like this:
 
    schemaname || '' AS schemaname,
 
for a number it might be changing:
 
    pg_total_relation_size(schemaname||'.'||tablename)
 
to:
 
    pg_total_relation_size(schemaname||'.'||tablename) + 0
 
Again, I would try without these first.  If the problem persists I
would sprinkle these throughout the query.  If the problem goes
away, I would probably selectively remove them until the problem
returned, so I would know where it matters.
 
-Kevin