Re: [HACKERS] type cache for concat functions

> On 20 May 2017 at 10:03, Pavel Stehule <pavel.stehule@gmail.com> wrote:

>

> Now concat is 2x times slower than || operator. With cached FmgrInfo for

> output function it will be only 5%.

Looks nice and does what's expected (what else one may need from a Saturday

evening). I just can mention that from what I see the previous version of

`concat` is slower the more arguments are getting involved, so looks like it

can be more than 2x.

Also, it was a little bit confusing to see that the function `concat` behaves

differently from operator `||` in terms of performance. When you're looking at

the code it's becoming obvious, but I couldn't find any mention about that in

the documentation.