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help / color / mirror / Atom feedFrom: Pavel Stehule <pavel.stehule@gmail.com>
To: remi duval <remi.duval@cheops.fr>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: proposal: schema variables
Date: Sat, 29 Feb 2020 10:09:47 +0100
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pá 28. 2. 2020 v 16:30 odesílatel Pavel Stehule <pavel.stehule@gmail.com>
napsal:
>
>
> čt 27. 2. 2020 v 15:37 odesílatel Pavel Stehule <pavel.stehule@gmail.com>
> napsal:
>
>>
>> Hi
>>
>>
>>> 3) Any way to define CONSTANTs ?
>>> We already talked a bit about this subject and also Gilles Darold
>>> introduces it in this mailing-list topic but I'd like to insist on it.
>>> I think it would be nice to have a way to say that a variable should not
>>> be changed once defined.
>>> Maybe it's hard to implement and can be implemented later, but I just
>>> want to know if this concern is open.
>>>
>>
>> I played little bit with it and I didn't find any nice solution, but
>> maybe I found the solution. I had ideas about some variants, but almost all
>> time I had a problem with parser's shifts because all potential keywords
>> are not reserved.
>>
>> last variant, but maybe best is using keyword WITH
>>
>> So the syntax can looks like
>>
>> CREATE [ TEMP ] VARIABLE varname [ AS ] type [ NOT NULL ] [ DEFAULT
>> expression ] [ WITH [ OPTIONS ] '(' ... ')' ] ]
>>
>> What do you think about this syntax? It doesn't need any new keyword, and
>> it easy to enhance it.
>>
>> CREATE VARIABLE foo AS int DEFAULT 10 WITH OPTIONS ( CONSTANT);
>>
>
> After some more thinking and because in other patch I support syntax
> CREATE TRANSACTION VARIABLE ... I change my opinion and implemented support
> for
> syntax CREATE IMMUTABLE VARIABLE for define constants.
>
second try to fix pg_dump
Regards
Pavel
>
> See attached patch
>
> Regards
>
> Pavel
>
>
>>
>> ?
>>
>> Regards
>>
>> Pavel
>>
>>
>>
Attachments:
[application/gzip] schema-variables-20200229.patch.gz (64.6K, 3-schema-variables-20200229.patch.gz)
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To: pgsql-performance@postgresql.org
Cc: pavel.stehule@gmail.com, remi.duval@cheops.fr, pgsql-hackers@lists.postgresql.org
Subject: Re: proposal: schema variables
In-Reply-To: <CAFj8pRALAZOu6bXTaz6CHox9S=OqHT-suX+LRgA4z0nzhXv4Vw@mail.gmail.com>
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