Horton

Re: pg_upgrade bug found!

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Bruce Momjian <bruce@momjian.us>
Cc: Jeff Davis <pgsql@j-davis.com>, RhodiumToad on IRC <andrew@tao11.riddles.org.uk>, Robert Haas <robertmhaas@gmail.com>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Alvaro Herrera <alvherre@commandprompt.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2011-04-07T21:36:10Z
Lists: pgsql-hackers 
Bruce Momjian wrote:
> Jeff Davis wrote:
> > On Thu, 2011-04-07 at 17:06 -0400, Bruce Momjian wrote:
> > > I want to avoid anything that requires a compile because they are hard
> > > for many sites to install so TransactionIdPrecedes() is out.  We will
> > > need to do this in PL/pgSQL probably.
> > 
> > PL/pgSQL can't see dead rows, so that would not be correct. It's
> > guaranteed to be the same value you see from the heap or newer; because
> > if it's not visible in the heap, it's not going to be visible in the
> > toast table.
> 
> Well, frankly all we need to do is set those hint bits before the clog
> gets remove, so maybe just a SELECT * would do the trick!  That and
> maybe set the relfrozenxid to match the heap.
> 
> It is there now or more people would be reporting problems.

Clarification, "the clog" is there now or more people would be reporting
problems.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +