Date: Mon, 12 Sep 2005 08:26:47 -0600
From: Michael Fuhr <mike@fuhr.org>
To: pgsql-docs@postgresql.org
Subject: Multicolumn index doc out of date?
Message-ID: <20050912142647.GA34685@winnie.fuhr.org>
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The 8.1 Release Notes have the following item:

  *  Allow non-consecutive index columns to be used in a multi-column index

So isn't the following paragraph from "Multicolumn Indexes" out of
date?

  The query planner can use a multicolumn index for queries that
  involve the leftmost column in the index definition plus any
  number of columns listed to the right of it, without a gap.  For
  example, an index on (a, b, c) can be used in queries involving
  all of a, b, and c, or in queries involving both a and b, or in
  queries involving only a, but not in other combinations.  (In a
  query involving a and c the planner could choose to use the index
  for a, while treating c like an ordinary unindexed column.)

http://developer.postgresql.org/docs/postgres/indexes-multicolumn.html

-- 
Michael Fuhr