Re: performance issue: logical operators are slow inside SQL function: missing optimalization? - Mailing list pgsql-hackers

Pavel Stehule <pavel.stehule@gmail.com> writes:
> 2010/8/29 Tom Lane <tgl@sss.pgh.pa.us>:
>> The one case is inline-able and the other not (because it would result
>> in double evaluation of the volatile function random()).
>> See EXPLAIN VERBOSE.

> I understand now. So it means general advice - don't use a boolean
> operators in SQL function? This issue should be documented somewhere?

It has nothing to do with boolean operators, just double evaluation.
        regards, tom lane