Chris Hoover wrote:
Well, the one index:
CREATE INDEX acceptedbilling_to_date
The second index is rather stupid, it was an early index before I
figured out how to split a timestamp.
Anyway, is there a way to make the first index work? Otherwise we end
up with a seq scan on our billing table which is very painful.
First, please do not top post:
http://www.catb.org/jargon/html/T/top-post.html
Second:
create function mydate(varchar) returns varchar AS $$ select
to_char($1::date,'YYYYMMDD'); $$ LANGUAGE SQL IMMUTABLE;
create index foobar on date_test(mydate(date));
You will need to test this, but it does allow you to create the index.
Sincerely,
Joshua D. Drake
Thanks,
Chris
On 6/6/07, *Tom Lane* <tgl@xxxxxxxxxxxxx <mailto:tgl@xxxxxxxxxxxxx>> wrote:
Alvaro Herrera <alvherre@xxxxxxxxxxxxxxxxx
<mailto:alvherre@xxxxxxxxxxxxxxxxx>> writes:
> You can't do this because to_date and other functions are not
immutable.
> 8.2 seems to be more picky about this -- the date conversions of
> timestamptz columns are dependent on the current timezone.
The reason 8.2 is more picky is that the function is less immutable
thanks to the addition of locale-dependent functionality:
http://archives.postgresql.org/pgsql-committers/2006-11/msg00264.php
I gather that the underlying column is timestamp without tz, or it would
never have worked in 8.1 either. That being the case, these index
definitions seem pretty darn stupid anyway --- why aren't you just
indexing on date_trunc or a plain cast to date?
regards, tom lane
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