On 02/26/2017 07:56 AM, Geoff Winkless wrote:
> On 26 February 2017 at 10:09, Sven R. Kunze <srku...@mail.de
> <mailto:srku...@mail.de>>wrote:
> 
>     >>># create index docs_birthdate_idx ON docs using btree
>     (((meta->>'birthdate')::date));
>     ERROR:  functions in index expression must be marked IMMUTABLE
> 
>     So, what is the problem here?
> 
> 
> ​Date functions are inherently not immutable because of timezones. Your
> solution of using to_timestamp doesn't help because it automatically
> returns a value in WITH TIMESTAMP. Do you get anywhere by using
> "::timestamp without time zone" instead, as suggested here?

My attempts at working the OP's problem passed through that:

test=> create index docs_birthdate_idx ON docs using btree 
(((meta->>'birthdate')::timestamp));
ERROR:  functions in index expression must be marked IMMUTABLE

This works:

test=> create index docs_birthdate_idx ON docs using btree 
((meta->>'birthdate'));
CREATE INDEX

It is the act of casting that fails. Other then the OP's own suggestion of 
creating
a function that wraps the operation and marks it immutable I don't have a 
solution at
this time.

> 
> https://www.postgresql.org/message-id/4E039D16.20704%40pinpointresearch.com
> 
> Geoff
> 
> ​


-- 
Adrian Klaver
adrian.kla...@aklaver.com


-- 
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

Reply via email to