Re: Possible solution for LIKE optimization

Hiroshi Inoue <Inoue@tpf.co.jp> writes:
>> Peter Eisentraut <peter_e@gmx.net> writes:
> Wait, why isn't that the solution in the first place.  Let's build the
> index with an opclass that uses plain strcmp comparison.

> Do we have to make 2 indexes for non_ASCII text field ?

You would if you want to use indexscans for both LIKE and "x < 'FOO'"
(ie, locale-aware comparisons).  Which is not great, but I think we've
finally seen the light: a locale-sorted index is just plain not useful
for LIKE.

This discussion has restored my faith in index opclasses; finally we
have a real-world application of 'em that we can point to ...
        regards, tom lane