Tim Allen <tim(at)proximity(dot)com(dot)au> writes:
> Thomas Hallgren wrote:
>> The position function must look for 'ch' everywhere in the string so
>> there's no way it can use an index.
> I think the '= 0' bit is what Chris was suggesting could be the basis
> for an optimisation.
Yeah. AFAICS the transformation Chris suggested is valid. I'm really
dubious that it's worth expending planner cycles to look for it though.
LIKE is something that everybody and his brother uses, but who uses this
position()=0 locution?
regards, tom lane