Re: Partial Indices vs. mixing columns and functions

Tom Lane wrote:
>
> Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > What kind of expression is allowed as the predicate now ?
>
> Anything that doesn't involve an aggregate or a subselect.
>
> (But what the planner can recognize as matching a query's
> WHERE clause is currently much more restricted, just ANDs
> and ORs of simple VAR OP CONST clauses.  This could be
> improved in the future.)
>
> > Both the functions used in functional indexes and the
> > predicates used in partial indexes must be deterministic.
> > Are users responsible for it ?
>
> Yes.  I don't see how the system could enforce that, without
> prohibiting lots of useful cases.
>

Shouldn't the functions be *cacheable* at least ?

regards,
Hiroshi Inoue