Re: subselect instead of a view...

On 26 Nov 2002 at 0:29, Tom Lane wrote:

> "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.

Thanks.  I'll see if I can come up with something else to do this.
-- 
Dan Langille : http://www.langille.org/