Re: yet another stupid question (index coverage) - Mailing list pgsql-general

From Peter Eisentraut
Subject Re: yet another stupid question (index coverage)
Date
Msg-id Pine.LNX.4.30.0105172343100.757-100000@peter.localdomain
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In response to yet another stupid question (index coverage)  (Alex Pilosov <alex@pilosoft.com>)
List pgsql-general
Alex Pilosov writes:

> Explain shows it is using index scan, however, it looks like database is
> fetching blocks from all over the disk, when all information necessary is
> already in index.

All except the all-important piece of information whether the tuple is
visible to the current transaction.  That you need to fetch from the main
table.

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter


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