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Re: [HACKERS] type cache for concat functions - Mailing list pgsql-hackers

From	Dmitry Dolgov
Subject	Re: [HACKERS] type cache for concat functions
Date	June 18, 2017 01:50:50
Msg-id	CA+q6zcX9=zD1-edrAni_4HXPL-PbjYDeYFdxD2-CEojdr0Pq9Q@mail.gmail.com Whole thread Raw
In response to	[HACKERS] type cache for concat functions (Pavel Stehule <pavel.stehule@gmail.com>)
Responses	Re: [HACKERS] type cache for concat functions
List	pgsql-hackers

> 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.

From: Peter Eisentraut
Date: 18 June 2017, 01:27:25
Subject: Re: [HACKERS] logical replication - still unstable after all thesemonths

From: Peter Eisentraut
Date: 18 June 2017, 02:03:48
Subject: Re: [HACKERS] Typo in planstats.sgml