Message-ID: <e0632341-8e71-b4ca-330c-955f3bf66b26@enterprisedb.com>
Date: Tue, 7 Dec 2021 16:52:42 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.3.2
Subject: Re: types reliant on encodings [was Re: Dubious usage of
 TYPCATEGORY_STRING]
Content-Language: en-US
To: Chapman Flack <chap@anastigmatix.net>, Tom Lane <tgl@sss.pgh.pa.us>,
 pgsql-hackers@lists.postgresql.org
References: <2216388.1638480141@sss.pgh.pa.us>
 <61AA6516.8000406@anastigmatix.net>
From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
In-Reply-To: <61AA6516.8000406@anastigmatix.net>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: 
 <https://www.postgresql.org/message-id/e0632341-8e71-b4ca-330c-955f3bf66b26%40enterprisedb.com>
Precedence: bulk

On 03.12.21 19:42, Chapman Flack wrote:
> Is there any way to find out, from the catalogs or in any automatable way,
> which types are implemented with a dependence on the database encoding
> (or on some encoding)?

What is this needed for?  C code can internally do whatever it wants, 
and the database encoding is effectively a constant, so there is no need 
for server-side code to be very much concerned about whether types do this.

Also, "types" is perhaps the wrong subject here.  Types only contain 
input and output functions and a few more bits.  Additional functions 
operating on the type could look at the server encoding without the type 
and its core functions knowing about it.