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In-Reply-To: <alpine.DEB.2.22.394.2012221025000.533489@pseudo>
From: Pavel Borisov <pashkin.elfe@gmail.com>
Date: Tue, 22 Dec 2020 19:03:05 +0400
Message-ID: 
 <CALT9ZEFe4Fj4mEnbpVmHQEXRC_K-DoicYvV-xHi0JZ3JTkc3Wg@mail.gmail.com>
Subject: Re: [PATCH] Automatic HASH and LIST partition creation
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: Maxim Orlov <m.orlov@postgrespro.ru>,
	Anastasia Lubennikova <a.lubennikova@postgrespro.ru>,
 Rahila Syed <rahilasyed90@gmail.com>,
	Michael Paquier <michael@paquier.xyz>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 Justin Pryzby <pryzby@telsasoft.com>,
	Robert Haas <robertmhaas@gmail.com>, Amul Sul <sulamul@gmail.com>
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>
> > CREATE TABLE foo(a int) PARTITION BY LIST(a) CONFIGURATION (FOR VALUES
> IN
> > (1,2),(3,4) DEFAULT PARTITION foo_def);
>
> I would like to disagree with this syntactic approach because it would
> very specific to each partition method. IMHO the syntax should be as
> generic as possible. I'd suggest (probably again) a keyword/value list
> which would allow to be quite adaptable without inducing any pressure on
> the parser.
>
If I remember your proposal correctly it is something like
CREATE TABLE foo(...) PARTITION BY HASH AUTOMATIC (MODULUS 10);

It is still possible but there are some caveats:
1. We'll need to add keyword MODULUS (and probably AUTOMATIC) to the
parser's list. I don't against this but as far as I've heard there is some
opposition among PG community against new keywords. Maybe I am wrong.
2. The existing syntax for declarative partitioning is different to your
proposal. It is still not a big problem and your proposal makes query
shorter for several words. I'd just like to see some consensus on the
syntax. Now I must admit there are too many contradictions in opinions
which make progress slow. Also I think it is important to have a really
convenient synta=D1=85.
2a Maybe we all who participated in the thread can vote for some variant?
2b Maybe the existing syntax for declarative partitioniong should be given
some priority as it is already committed into CREATE TABLE ... PARTITION OF
... FOR VALUES IN.. etc.

I'd be happy if everyone will join some version of the proposed synta=D1=85=
 in
this thread and in the previous discussion [1]. If we have a variant with
more than one supporter, sure we can develop patch based on it.
Thank you very much
and Merry Christmas!

[1]
https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1907150711080.22=
273%40lancre

--=20
Best regards,
Pavel Borisov

Postgres Professional: http://postgrespro.com <http://www.postgrespro.com>

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<div dir=3D"ltr"><div class=3D"gmail_quote"><blockquote class=3D"gmail_quot=
e" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204)=
;padding-left:1ex">&gt; CREATE TABLE foo(a int) PARTITION BY LIST(a) CONFIG=
URATION (FOR VALUES IN <br>
&gt; (1,2),(3,4) DEFAULT PARTITION foo_def);<br>
<br>
I would like to disagree with this syntactic approach because it would <br>
very specific to each partition method. IMHO the syntax should be as <br>
generic as possible. I&#39;d suggest (probably again) a keyword/value list =
<br>
which would allow to be quite adaptable without inducing any pressure on <b=
r>
the parser.<br></blockquote><div>If I remember your proposal correctly it i=
s something like</div><div><span style=3D"color:rgb(13,10,11);font-family:m=
onospace,monospace;font-size:10.7333px;white-space:pre-wrap">CREATE TABLE f=
oo(...) PARTITION BY HASH AUTOMATIC (MODULUS 10);</span></div><div><br></di=
v><div>It is still possible but there are some caveats:</div><div>1. We&#39=
;ll need to add keyword MODULUS (and probably AUTOMATIC) to the parser&#39;=
s list. I don&#39;t against this but as far as I&#39;ve heard there is some=
 opposition among PG community against new keywords. Maybe I am wrong.</div=
><div>2. The existing syntax for declarative partitioning is different to y=
our proposal. It is still not a big problem and your proposal makes query s=
horter for several words. I&#39;d just like to see some consensus on the sy=
ntax. Now I must admit there are too many contradictions in opinions which =
make progress slow. Also I think it is important to have a really convenien=
t synta=D1=85.</div><div>2a Maybe we all who participated in the thread can=
 vote for some variant?</div><div>2b Maybe the existing syntax for declarat=
ive partitioniong=C2=A0should be given some priority as it is already commi=
tted into CREATE TABLE ... PARTITION OF ... FOR VALUES IN.. etc.</div><div>=
<br></div><div>I&#39;d be happy if everyone will join some version of the p=
roposed synta=D1=85 in this thread and in the previous discussion [1]. If w=
e have a variant with more than one supporter, sure we can develop patch ba=
sed on it.</div><div>Thank you very much</div><div>and Merry Christmas!</di=
v><div><br></div><div>[1]=C2=A0<a href=3D"https://www.postgresql.org/messag=
e-id/flat/alpine.DEB.2.21.1907150711080.22273%40lancre">https://www.postgre=
sql.org/message-id/flat/alpine.DEB.2.21.1907150711080.22273%40lancre</a></d=
iv><div><br></div><div>--=C2=A0<br></div></div><div dir=3D"ltr" class=3D"gm=
ail_signature" data-smartmail=3D"gmail_signature"><div dir=3D"ltr"><div>Bes=
t regards,<br>Pavel Borisov<br><br>Postgres Professional: <a href=3D"http:/=
/www.postgrespro.com" rel=3D"noopener noreferrer" target=3D"_blank">http://=
postgrespro.com</a><br></div></div></div></div>

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