Postgres Pro
Downloads
Home   >   mailing lists

Re: [GENERAL] ERROR: functions in index expression must be markedIMMUTABLE - Mailing list pgsql-general

From Sven R. Kunze
Subject Re: [GENERAL] ERROR: functions in index expression must be markedIMMUTABLE
Date
Msg-id 4e4d464d-efa7-f004-4070-31457dfead7e@mail.de
Whole thread Raw
In response to Re: [GENERAL] ERROR: functions in index expression must be marked IMMUTABLE  (Geoff Winkless <pgsqladmin@geoff.dj>)
List pgsql-general
Tree view
On 03.03.2017 11:43, Geoff Winkless wrote:
One alternative would be to make to_date accept all language variants of months simultaneously. A quick search of google suggests that there aren't any overlaps between languages (ie where one language uses "Foo" for March and another uses "Foo" for May), although you would have to​ do some more intense research to be sure. As far as I can see there's no other reason why to_date would need to be marked as stable/volatile, is there?

I don't think so. It could be viable.

On the down side I imagine it would involve some potentially-prohibitively-large lookup tables; it would also end up with a technical incompatibility in that what ANSI SQL would reject as not-a-date might be parsed as a date.

There is another issue: languages change (admittedly very slowly) but I wouldn't want PostgreSQL to be incompatible with future generations.
Your performance argument weighs heavier, though.

I'm not in a position to judge if either of those would be acceptable.

Do you think I should post to pgsql-hackers?


Sven

pgsql-general by date:

Previous
From: Geoff Winkless
Date:
Subject: Re: [GENERAL] ERROR: functions in index expression must be marked IMMUTABLE
Next
From: Rui Pacheco
Date:
Subject: [GENERAL] PortalSuspended