Обсуждение: remove convert using

The attached patch removes "convert ... using ..." as recently discussed
on -hackers. Most of the patch is regression test changes.

If there's no objection I'll apply it in a day or two.

cheers

andrew

Andrew Dunstan <andrew@dunslane.net> writes:
> The attached patch removes "convert ... using ..." as recently discussed
> on -hackers. Most of the patch is regression test changes.

You should be able to remove CONVERT as a grammar keyword altogether
-- the remaining production for CONVERT as a function name seems dead
weight now (not to mention that it prevents having user-defined
functions named CONVERT).

Other than that omission it looks sane to me.

            regards, tom lane

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>
>> The attached patch removes "convert ... using ..." as recently discussed
>> on -hackers. Most of the patch is regression test changes.
>>
>
> You should be able to remove CONVERT as a grammar keyword altogether
> -- the remaining production for CONVERT as a function name seems dead
> weight now (not to mention that it prevents having user-defined
> functions named CONVERT).
>
>
>

I wonderted a bit about that. I thought it might be better to leave it
in case we wanted to put back "convert using" when we have better
support for multiple encodings (and maybe when we understand better what
it is actually supposed to do).

But I have no strong opinions on the subject.

cheers

anmdrew

Andrew Dunstan <andrew@dunslane.net> writes:
> Tom Lane wrote:
>> You should be able to remove CONVERT as a grammar keyword altogether
>> -- the remaining production for CONVERT as a function name seems dead
>> weight now (not to mention that it prevents having user-defined
>> functions named CONVERT).

> I wonderted a bit about that. I thought it might be better to leave it
> in case we wanted to put back "convert using" when we have better
> support for multiple encodings (and maybe when we understand better what
> it is actually supposed to do).

Well, we could always put it back when we need it --- in the meantime,
every extra keyword is some fractional drag on parsing performance.

In any case I think the remaining production is probably wrong because
it constrains the function to be in pg_catalog schema, when there is
no grammatical evidence that it should be special.

            regards, tom lane

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>
>> Tom Lane wrote:
>>
>>> You should be able to remove CONVERT as a grammar keyword altogether
>>> -- the remaining production for CONVERT as a function name seems dead
>>> weight now (not to mention that it prevents having user-defined
>>> functions named CONVERT).
>>>
>
>
>> I wonderted a bit about that. I thought it might be better to leave it
>> in case we wanted to put back "convert using" when we have better
>> support for multiple encodings (and maybe when we understand better what
>> it is actually supposed to do).
>>
>
> Well, we could always put it back when we need it --- in the meantime,
> every extra keyword is some fractional drag on parsing performance.
>
> In any case I think the remaining production is probably wrong because
> it constrains the function to be in pg_catalog schema, when there is
> no grammatical evidence that it should be special.
>

OK, fix committed doing this.

cheers

andrew