"Dan Langille" <dan@langille.org> writes:
> SELECT E.name, EP.pathname, E.id, EP2.pathname, CL.id
> ...
> and EP2.pathname like EP.pathname || '/%'
> I am still suspicous of that like. It seems to be the performance
> killer here. There is an index which can be used:
It won't be, though. The LIKE-to-indexscan transformation happens at
plan time, and that means it can only happen if the pattern is a
constant. Which it surely will not be in your example.
regards, tom lane