On Thu, Jun 28, 2012 at 9:12 AM, Alvaro Herrera <alvhe...@commandprompt.com> wrote: > > 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 seems like an easy question to answer. How could it not disable HOT and still work correctly? > That could be a > significant difference. True, adding the covering column would not always be a win. But surely it more likely to be a win when it can be done without adding yet another index that also needs to be maintained. Cheers, Jeff -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers