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List:       postgresql-general
Subject:    Re: [HACKERS] Indexing dead tuples
From:       Tom Lane <tgl () sss ! pgh ! pa ! us>
Date:       2005-08-31 23:06:25
Message-ID: 5483.1125529585 () sss ! pgh ! pa ! us
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Andrew - Supernews <andrew+nonews@supernews.com> writes:
> On 2005-08-31, Simon Riggs <simon@2ndquadrant.com> wrote:
>> During CREATE INDEX we include all tuples, even if they are already dead
>> when we build an index.
>> 
>> What purpose does this serve?
>> 
>> A pre-existing transaction can't see the index,

> Yes, it can; the catalog is read in SnapshotNow rather than in the query
> snapshot.

In fact, it had better be able to, since once the CREATE INDEX commits,
pre-existing xacts are responsible to insert index entries for anything
they insert into the table.

			regards, tom lane

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