From: Andy Fan <zhihuifan1213@163.com>
To: Andreas Karlsson <andreas@proxel.se>
Cc: David Rowley <dgrowleyml@gmail.com>,  pgsql-hackers
 <pgsql-hackers@postgresql.org>,  Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: Make printtup a bit faster
In-Reply-To: <def59c4b-9827-43b9-b7b6-800d712ad94e@proxel.se> (Andreas
	Karlsson's message of "Fri, 30 Aug 2024 18:20:39 +0200")
References: <87wmjzfz0h.fsf@163.com>
	<CAApHDvrBNA-QRsbn-SJyRAsywjHCNenfcbi14c3O3c7=OimQ8Q@mail.gmail.com>
	<def59c4b-9827-43b9-b7b6-800d712ad94e@proxel.se>
Date: Wed, 11 Sep 2024 09:02:50 +0800
Message-ID: <87wmjj80jp.fsf@163.com>
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Hello David & Andreas, 

> On 8/29/24 1:51 PM, David Rowley wrote:
>> I had planned to work on this for PG18, but I'd be happy for some
>> assistance if you're willing.
>
> I am interested in working on this, unless Andy Fan wants to do this
> work. :) I believe that optimizing the out, in and send functions would
> be worth the pain. I get Tom's objections but I do not think adding a
> small check would add much overhead compared to the gains we can get.

Just to be clearer, I'd like work on the out function only due to my
internal assignment. (Since David planned it for PG18, so it is better
say things clearer eariler). I'd put parts of out(print) function
refactor in the next 2 days. I think it deserves a double check before
working on *all* the out function.

select count(*), count(distinct typoutput) from pg_type;
 count | count 
-------+-------
   621 |    97
(1 row)

select typoutput, count(*) from pg_type group by typoutput having
    count(*) > 1 order by 2 desc;
    
    typoutput    | count 
-----------------+-------
 array_out       |   296
 record_out      |   214
 multirange_out  |     6
 range_out       |     6
 varcharout      |     3
 int4out         |     2
 timestamptz_out |     2
 nameout         |     2
 textout         |     2
(9 rows)

-- 
Best Regards
Andy Fan