Re: query planner: automatic rescribe of LIKE to BETWEEN ?

On 8/22/06, Alvaro Herrera <alvherre@commandprompt.com> wrote:
> Ulrich Habel wrote:
> > Hello all,
> > had an idea of optimizing a query that may work generally.
> >
> > In case a 'column' is indexed, following two alterations could be done
> > I think:
> >
> > A)
> >
> >   select ... where column ~ '^Foo'     -->  Seq Scan
>
> This is not true.  You can make this query use an index if you create it
> with opclass varchar_pattern_ops or text_pattern_ops, as appropiate.
>
> Thus you don't need any hack here.
>

And in the case of more general expression, like:
 select ... where column ~ 'something';

Is there a way to optimise this ? (in the case where 'something' is not
a word, but a part of a word)

--
Thomas SAMSON