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help / color / mirror / Atom feedFrom: Pavel Stehule <pavel.stehule@gmail.com>
To: Arthur Zakirov <a.zakirov@postgrespro.ru>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] proposal: schema variables
Date: Wed, 18 Apr 2018 13:54:44 +0200
Message-ID: <CAFj8pRBLTM6hetPRN1fKv-+MCYZKK9=Rk3n6xhKumt-vxE=E_Q@mail.gmail.com> (raw)
In-Reply-To: <20180418113710.GA8232@zakirov.localdomain>
References: <CAFj8pRDY+m9OOxfO10R7J0PAkCCauM-TweaTrdsrsLGMb1VbEQ@mail.gmail.com>
<20180417141410.GA7917@zakirov.localdomain>
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<20180418113710.GA8232@zakirov.localdomain>
Hi
I am sending rebased patch
2018-04-18 13:37 GMT+02:00 Arthur Zakirov <a.zakirov@postgrespro.ru>:
> On Tue, Apr 17, 2018 at 06:28:19PM +0200, Pavel Stehule wrote:
> > I though about it, and I am inclined to prefer pg_class instead separate
> > tables.
> >
> > 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.
> >
> > There are two objective arguments for using pg_class:
> >
> > 1. unique name in schema - it reduces risk of collisions
> > 2. sharing lot of code
> >
> > So in this case I don't see well benefits of separate table.
>
> Understood. I haven't strong opinion here though. But I thought that
> pg_class approach may limit extensibility of variables.
>
I didn't touch limit (I don't know if there will be some issue - still is
far to upstream). This is technology, but workable, demo. I though so some
users had a problem to imagine what is persistent variable in my view.
But almost all code and tests can be used for final version - only storage
implementation is nothing more than workaround.
>
> BTW:
> - there is unitialized variable 'j' in pg_dump.c:15422
> - in tab-complete.c:1268 initialization needs extra NULL before
> &Query_for_list_of_variables
>
I found it too today when I did rebase. But thank you for report.
>
> Also I think makeRangeVarForTargetOfSchemaVariable() has non friendly
> argument names 'field1', 'field2', 'field2'.
>
yes, I hadn't better names :(
In this routine I am doing diagnostic what semantic has sense for current
values. the field1, field2 can be schema.variable or variable.field. So
when I used semantic names: schema, varname, fieldname, then it was more
messy (for me).
Regards
Pavel
>
> --
> Arthur Zakirov
> Postgres Professional: http://www.postgrespro.com
> Russian Postgres Company
>
Attachments:
[application/octet-stream] schema-variables-poc-180418-01-diff (174.1K, 3-schema-variables-poc-180418-01-diff)
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To: pgsql-performance@postgresql.org
Cc: pavel.stehule@gmail.com, a.zakirov@postgrespro.ru, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] proposal: schema variables
In-Reply-To: <CAFj8pRBLTM6hetPRN1fKv-+MCYZKK9=Rk3n6xhKumt-vxE=E_Q@mail.gmail.com>
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