Re: [SQL] Duplicate tuples with unique index

> Bruce thinks that the pg_upgrade script will ensure that the system-
> table tuples are all in frozen states (by VACUUMing them).  I don't
> trust it worth a dime, myself.  Maybe it will work, but it hasn't been
> proven in the field.  So, if you'd like to try it, by all means do so
> --- but make a pg_dump backup first!  And let us know whether you have
> problems or not!

I see what you are saying.  If a table created as part of the new
pg_dump schema create matches a transaction that aborted in the old
database, the table would be invalid.  However, as you mentioned, once
the tuple is marked as committed/rolled back, it doesn't consult.

Basically, I was surprised pg_upgrade worked at all in any of the
releases.  It seems too good to be true.  However, I have received very
few problem reports about its use, and it does get used.

--  Bruce Momjian                        |  http://www.op.net/~candle pgman@candle.pha.pa.us               |  (610)
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