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To: Robert Haas <robertmhaas@gmail.com>
cc: Tatsuo Ishii <ishii@postgresql.org>, mangoo@wpkg.org,
	scott.marlowe@gmail.com, t-ishii@sra.co.jp,
	Kevin.Grittner@wicourts.gov, pgsql-hackers@postgresql.org
Subject: Re: pgpool versus sequences 
In-reply-to: <27741.1306968830@sss.pgh.pa.us> 
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Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Wed, 01 Jun 2011 18:53:50 -0400"
Date: Wed, 01 Jun 2011 20:15:40 -0400
Message-ID: <29868.1306973740@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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I wrote:
> Please note also that what pgpool users have got right now is a time
> bomb, which is not better than immediately-visible breakage.

BTW, so far as that goes, I suggest that we tweak nextval() and setval()
to force the sequence tuple's xmax to zero.  That will provide a simple
recovery path for anyone who's at risk at the moment.  Of course, this
has to go hand-in-hand with the change to forbid SELECT FOR UPDATE,
else those operations would risk breaking active tuple locks.

			regards, tom lane