Re: Re: Buffer access rules, and a probable bug

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp>
Cc: "Mikheev, Vadim" <vmikheev(at)SECTORBASE(dot)COM>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Re: Buffer access rules, and a probable bug
Date: 2001-07-05 13:54:43
Message-ID: 2758.994341283@sss.pgh.pa.us
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Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp> writes:
> Dead(HEAP_XMAX_COMMITTED || HEAP_XMIN_INVALID) tuples never
> revive. Live (not dead) tuples never die in Share Lock mode.

Hmm ... so you're relying on the ShareLock to ensure that the state of
the tuple can't change between when heap_fetch checks it and when
nbtree looks at it.

Okay, but put in some comments documenting what this stuff is doing
and why.

regards, tom lane

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