From: Alexey Kondratov <a.kondratov@postgrespro.ru>
To: Robert Haas <robertmhaas@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Surafel Temesgen <surafel3000@gmail.com>
Cc: Alexander Korotkov <a.korotkov@postgrespro.ru>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Allow CLUSTER, VACUUM FULL and REINDEX to change tablespace on the fly
Date: Thu, 19 Sep 2019 17:40:41 +0300
Message-ID: <f4881081-14cd-46d2-8e81-75003a7a7c83@postgrespro.ru> (raw)
In-Reply-To: <CA+Tgmoae6pTLmz-oEHXFbEXGAQm6FCP9D5fF2KXLpbg2u0SJbg@mail.gmail.com>
References: <f3255cfc-a395-133a-17d1-5fca873e7b05@postgrespro.ru>
<20181227132417.xe3oagawina7775b@alvherre.pgsql>
<CAD21AoCOsHnu2wLOaHgcZ4yJp7kaQkWfyhLzD4tjh6k4k4nhAA@mail.gmail.com>
<CAPpHfdunJ4o5w9ndtOeAEt_h_H+XoZpgopK+NCsA30xeZTE8kw@mail.gmail.com>
<6b2a5c4de19f111ef24b63428033bb67@postgrespro.ru>
<CALAY4q-0oU4ORb07C4BxvGXgetBswqS1V5e2JP1wTV5q+O7-tA@mail.gmail.com>
<34493046-cbda-3262-2ff9-4189bccfb862@postgrespro.ru>
<20190919044300.GB21144@paquier.xyz>
<CA+Tgmoae6pTLmz-oEHXFbEXGAQm6FCP9D5fF2KXLpbg2u0SJbg@mail.gmail.com>
On 19.09.2019 16:21, Robert Haas wrote:
> On Thu, Sep 19, 2019 at 12:43 AM Michael Paquier <michael@paquier.xyz> wrote:
>> It seems to me that it would be good to keep the patch as simple as
>> possible for its first version, and split it into two if you would
>> like to add this new option instead of bundling both together. This
>> makes the review of one and the other more simple. Anyway, regarding
>> the grammar, is SET TABLESPACE really our best choice here? What
>> about:
>> - TABLESPACE = foo, in parenthesis only?
>> - Only using TABLESPACE, without SET at the end of the query?
>>
>> SET is used in ALTER TABLE per the set of subqueries available there,
>> but that's not the case of REINDEX.
> So, earlier in this thread, I suggested making this part of ALTER
> TABLE, and several people seemed to like that idea. Did we have a
> reason for dropping that approach?
If we add this option to REINDEX, then for 'ALTER TABLE tb_name action1,
REINDEX SET TABLESPACE tbsp_name, action3' action2 will be just a direct
alias to 'REINDEX TABLE tb_name SET TABLESPACE tbsp_name'. So it seems
practical to do this for REINDEX first.
The only one concern I have against adding REINDEX to ALTER TABLE in
this context is that it will allow user to write such a chimera:
ALTER TABLE tb_name REINDEX SET TABLESPACE tbsp_name, SET TABLESPACE
tbsp_name;
when they want to move both table and all the indexes. Because simple
ALTER TABLE tb_name REINDEX, SET TABLESPACE tbsp_name;
looks ambiguous. Should it change tablespace of table, indexes or both?
--
Alexey Kondratov
Postgres Professional https://www.postgrespro.com
Russian Postgres Company
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To: pgsql-hackers@postgresql.org
Cc: a.kondratov@postgrespro.ru, robertmhaas@gmail.com, michael@paquier.xyz, surafel3000@gmail.com, a.korotkov@postgrespro.ru, sawada.mshk@gmail.com, alvherre@2ndquadrant.com
Subject: Re: Allow CLUSTER, VACUUM FULL and REINDEX to change tablespace on the fly
In-Reply-To: <f4881081-14cd-46d2-8e81-75003a7a7c83@postgrespro.ru>
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