Re: Possible solution for LIKE optimization

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> Tom Lane writes:
>> On the other hand, LIKE *is* multibyte aware. So the hypothetical
>> non-locale-aware comparison operators would need to be aware of
>> multibyte character sets even though not aware of locale. And the
>> "add one" operator that we postulated for the LIKE index optimization
>> needs to be able to increment a multibyte character.

> Both of these are not hard if you know how strcmp operates. It would also
> be irrelevant whether "add one" to a multibyte character yields another
> valid multibyte character. strcmp doesn't care.

I imagine we can come up with a definition that makes LIKE optimization
work. I was wondering more about Hiroshi's implied question: would such
an index have any use for sorting? Or would the induced sort order (on
multibyte character sets) look too weird to be of any use?

regards, tom lane