On Apr 1, 2011, at 4:48 PM, Bruce Momjian wrote:
> I am not so concerned about this case but about other cases where we are
> computing xid distances across the invalid range.

Bruce, I think you hit the nail on the head earlier:

> To do the right thing every computation that passes over the xid
> wraparound bounary should subtract FirstNormalTransactionId, not just
> those that fall in the boundry.

Put another way: XID calculations should not use just +/-, but an operator (presumably a macro) that understands wraparound and the special values. Surely we have a similar problem in the code that increments XIDs, and possibly other places as well.
--
Jim C. Nasby, Database Architect                   jim(at)nasby(dot)net
512.569.9461 (cell)                         http://jim.nasby.net

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• Re: Bug in autovacuum.c? at 2011-04-01 21:48:16 from Bruce Momjian

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