how can i mark date function like iscachable - Mailing list pgsql-general

erobles wrote:
> Hello there!
>
> i tried to  create an functional index  like this:
>
> create index estdistfecha on estadist (date(fecha));
>
>
> but only get the  next message:
> ERROR: DefineIndex: index function must be marked iscachable.
>
> So, How can i mark the date function iscachable ? :-)
>
> i hope your anwsers, anyway thanks to read this !
>
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