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Date: Tue, 31 Jan 2023 11:21:12 +0100
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Subject: Re: Named Operators
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To: Matthias van de Meent <boekewurm+postgres@gmail.com>
Cc: Gurjeet Singh <gurjeet@singh.im>,
 Postgres Hackers <pgsql-hackers@postgresql.org>
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From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
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On 27.01.23 16:34, Matthias van de Meent wrote:
> On Fri, 27 Jan 2023 at 16:26, Peter Eisentraut
> <peter.eisentraut@enterprisedb.com> wrote:
>>
>> On 12.01.23 14:55, Matthias van de Meent wrote:
>>>> Matter of taste, I guess. But more importantly, defining an operator
>>>> gives you many additional features that the planner can use to
>>>> optimize your query differently, which it can't do with functions. See
>>>> the COMMUTATOR, HASHES, etc. clause in the CREATE OPERATOR command.
>>> I see. Wouldn't it be better then to instead make it possible for the
>>> planner to detect the use of the functions used in operators and treat
>>> them as aliases of the operator? Or am I missing something w.r.t.
>>> differences between operator and function invocation?
>>>
>>> E.g. indexes on `int8pl(my_bigint, 1)` does not match queries for
>>> `my_bigint + 1` (and vice versa), while they should be able to support
>>> that, as OPERATOR(pg_catalog.+(int8, int8)) 's function is int8pl.
>>
>> I have been thinking about something like this for a long time.
>> Basically, we would merge pg_proc and pg_operator internally.  Then, all
>> the special treatment for operators would also be available to
>> two-argument functions.
> 
> And single-argument functions in case of prefix operators, right?

Right.

(The removal of postfix operators is helpful to remove ambiguity here.)