Re: Covering Indexes - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Covering Indexes
Date
Msg-id 1340899866-sup-4764@alvh.no-ip.org
Whole thread Raw
In response to Re: Covering Indexes  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Covering Indexes  (Aidan Van Dyk <aidan@highrise.ca>)
Re: Covering Indexes  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Covering Indexes  (Jeff Janes <jeff.janes@gmail.com>)
List 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>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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