public inbox for pgsql-performance@postgresql.org
help / color / mirror / Atom feedFrom: Pavel Stehule <pavel.stehule@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Arthur Zakirov <a.zakirov@postgrespro.ru>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] proposal: schema variables
Date: Fri, 20 Apr 2018 19:45:06 +0200
Message-ID: <CAFj8pRCptLktoDiCYK_rL2OgOGR-+B1QrNUGcK+Mkqi+KhWj+g@mail.gmail.com> (raw)
In-Reply-To: <CA+Tgmoaf44_UONp7zHgmkRwFNPbr7-7XnuZYu_JqSdZMrLi3cA@mail.gmail.com>
References: <CAFj8pRDY+m9OOxfO10R7J0PAkCCauM-TweaTrdsrsLGMb1VbEQ@mail.gmail.com>
<20180417141410.GA7917@zakirov.localdomain>
<CAFj8pRD3RGW7zoHs2-4FgUKnV7TmHYbZiQYq1KS+KgwS3W30bQ@mail.gmail.com>
<CA+Tgmoaf44_UONp7zHgmkRwFNPbr7-7XnuZYu_JqSdZMrLi3cA@mail.gmail.com>
2018-04-20 17:32 GMT+02:00 Robert Haas <robertmhaas@gmail.com>:
> On Tue, Apr 17, 2018 at 12:28 PM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
> > It true, so there are lot of "unused" attributes for this purpose, but
> there
> > is lot of shared attributes, and lot of shared code. Semantically, I see
> > variables in family of sequences, tables, indexes, views. Now, it shares
> > code, and I hope in next steps more code can be shared - constraints,
> > triggers.
>
> I dunno, it seems awfully different to me. There's only one "column",
> right? What code is really shared here? Are constraints and triggers
> even desirable feature for variables? What would be the use case?
>
The schema variable can hold composite value. The patch allows to use any
composite type or adhoc composite values
DECLARE x AS compositetype;
DECLARE x AS (a int, b int, c int);
Constraints are clear, no.
Triggers are strange maybe, but why not - it can be used like enhanced
constraints, can be used for some value calculations, ..
> I think stuffing this into pg_class is pretty strange.
>
It will be if variable is just scalar value without any possibilities. But
then there is only low benefit
The access rights implementation is shared with other from pg_class too.
Regards
Pavel
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: pavel.stehule@gmail.com, robertmhaas@gmail.com, a.zakirov@postgrespro.ru, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] proposal: schema variables
In-Reply-To: <CAFj8pRCptLktoDiCYK_rL2OgOGR-+B1QrNUGcK+Mkqi+KhWj+g@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox