Re: Partitioned tables and covering indexes

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Peter Geoghegan <pg@bowt.ie>, Alexander Korotkov <a.korotkov@postgrespro.ru>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Teodor Sigaev <teodor@sigaev.ru>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Jaime Casanova <jaime.casanova@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-11T21:29:38Z
Lists: pgsql-hackers
On 4/11/18 17:08, Peter Geoghegan wrote:
>> However, I don't see any point in defining collations here, because
>> INCLUDE attributes exist solely for index-only scans.  So, index just
>> can return value of INCLUDE attribute "as is", no point to do something
>> with collation.
>>
>> So, I propose to disable collations for INCLUDE attributes.
> Hmm. I'm not sure that that's exactly the right thing to do. We seem
> to want to have case-insensitive collations in the future. The fact
> that you can spell out collation name in ON CONFLICT's unique index
> inference specification suggests this, for example. I think that a
> collation is theoretically allowed to affect the behavior of equality,
> even though so far we've never tried to make that work for any
> collatable datatype.

But in this case it doesn't even do equality comparison, it just returns
the value.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


Commits

  1. Fix interference between covering indexes and partitioned tables

  2. Cleanup covering infrastructure

  3. Rename IndexInfo.ii_KeyAttrNumbers array