From: | Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> |
---|---|
To: | me(at)alternize(dot)com |
Cc: | Michael Glaesemann <grzm(at)myrealbox(dot)com>, Michael Fuhr <mike(at)fuhr(dot)org>, pgsql-novice(at)postgresql(dot)org |
Subject: | Re: help with query: advanced ORDER BY... |
Date: | 2006-01-15 18:33:48 |
Message-ID: | 20060115101603.P57128@megazone.bigpanda.com |
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Thread: | |
Lists: | pgsql-novice |
On Sun, 15 Jan 2006 me(at)alternize(dot)com wrote:
> > Something you may consider doing is creating a view that masks the
> > screen_number in those cases, something like
> >
> > create view schedule_public_view as
> > select theater_id
> > , screen_date
> > , screen_time
> > , case when no_screen_number then 0 else screen_number end as
> > screen_number
> > , movie_name
> > from schedules;
>
> wouldn't this be the same problem: pgsql not using the index for
> screen_number anymore?
Theoretically an expressional index with the case expression should be
usable for sorting with more complicated expressions like that. That
really only an option if theres a small number of fixed orders though (and
in testing it looked like you might need to play with settings to get it
chosen).
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