Horton

Re: Covering Indexes

Alvaro Herrera <alvherre@commandprompt.com>

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From: Alvaro Herrera <alvherre@commandprompt.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew@dunslane.net>, Jeff Janes <jeff.janes@gmail.com>, David E. Wheeler <david@justatheory.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-06-28T16:12:14Z
Lists: pgsql-hackers 
Excerpts from Tom Lane's message of jue jun 28 12:07:58 -0400 2012:

> When this came up a couple weeks ago, the argument that was made for it
> was that you could attach non-significant columns to an index that *is*
> unique.  That might or might not be a wide enough use-case to justify
> adding such a horrid kludge.

The other question is whether such an index would prevent an update from
being HOT when the non-indexed values are touched.  That could be a
significant difference.

-- 
Álvaro Herrera <alvherre@commandprompt.com>
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