From: | "Albe Laurenz" <laurenz(dot)albe(at)wien(dot)gv(dot)at> |
---|---|
To: | "Paul Hartley *EXTERN*" <phartley(at)gmail(dot)com>, <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: different sort order for primary key index |
Date: | 2009-10-14 12:58:18 |
Message-ID: | D960CB61B694CF459DCFB4B0128514C203937F8C@exadv11.host.magwien.gv.at |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
Paul Hartley wrote:
> I have a composite primary key for a table, let's call it
> (col1, col2). When this table is created, obviously an
> implicit index is created for this key. I would like the
> sort order of this index to be different for the two columns
> -- if I were to create the index myself, I would pass on
> (col1, col2 DESC). The ALTER INDEX documentation suggests
> that it's not possible to change the sort order of a column,
> so I can envision two ways to get around this: 1) create a
> second UNIQUE index of (col1, col2 DESC), or 2) not define a
> primary key and just specify a UNIQUE index separately.
> Primary keys are basically restricted to being unique and
> non-null, but I'm unclear if PostgreSQL treats primary keys
> differently from unique, non-null constraints.
I think you can safely go for 2).
Although I admit it is not pretty.
Yours,
Laurenz Albe
From | Date | Subject | |
---|---|---|---|
Next Message | Grzegorz Jaśkiewicz | 2009-10-14 13:16:30 | Re: different sort order for primary key index |
Previous Message | Craig Ringer | 2009-10-14 11:11:23 | Re: Cannot start the postgres service |