| From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Andrew Dunstan <andrew(at)dunslane(dot)net>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, David E(dot) Wheeler <david(at)justatheory(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Covering Indexes |
| Date: | 2012-06-28 16:12:14 |
| Message-ID: | 1340899866-sup-4764@alvh.no-ip.org |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| 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(at)commandprompt(dot)com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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