Re: Allow multi-byte characters as escape in SIMILAR TO and SUBSTRING

On 08/27/2014 08:13 AM, Jeff Davis wrote:
> On Mon, 2014-08-25 at 17:41 +0300, Heikki Linnakangas wrote:
>> your patch seems to be about 2x-3x as slow as unpatched master. So this
>> needs some optimization. A couple of ideas:
>
> I didn't see anywhere near that kind of regression. On unpatched master,
> with your test case, I saw it stabilize to about 680ms. With
> similar-escape-1, I saw about 775ms (15% regression). Are those at all
> close to your numbers? Is there a chance you used an unoptimized build
> for one of them, or left asserts enabled?

Oh. I can't now reproduce my earlier results either, I must've messed up
something. I'm now seeing similar numbers as you.

> Attached a patch implementing the same idea though: only use the
> multibyte path if *both* the escape char and the current character from
> the pattern are multibyte.
>
> I also changed the comment to more clearly state the behavior upon which
> we're relying. I hope what I said is accurate.

s/the the/the/. Other than that, looks good to me.

- Heikki