Date: Fri, 2 Aug 2019 21:48:59 +0200
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: Andrey Borodin <x4mmm@yandex-team.ru>,
	Konstantin Knizhnik <k.knizhnik@postgrespro.ru>,
	Michael Paquier <michael@paquier.xyz>,
	pgsql-hackers <pgsql-hackers@postgresql.org>,
	Vladimir Leskov <vladimirlesk@yandex-team.ru>
Subject: Re: pglz performance
Message-ID: <20190802194859.qxzxq2achzottkup@development>
References: <20190513071427.GB2273@paquier.xyz>
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 <ea57b49a-ecf0-481a-a77b-631833354f7d@postgrespro.ru>
 <20190802144345.d62jtiyyx6r2y73f@development>
 <DBB2A9E5-29FD-40BF-AC60-BD990FBF142F@yandex-team.ru>
 <20190802163948.i6mjypdgujeorrbi@alap3.anarazel.de>
 <20190802170039.o4pabnzm4xy3z7uj@development>
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On Fri, Aug 02, 2019 at 11:20:03AM -0700, Andres Freund wrote:
>Hi,
>
>On 2019-08-02 19:52:39 +0200, Tomas Vondra wrote:
>> Hmmm, I don't remember the details of those patches so I didn't realize
>> it allows incremental recompression. If that's possible, that would mean
>> existing systems can start using it. Which is good.
>
>That depends on what do you mean by "incremental"? A single toasted
>datum can only have one compression type, because we only update them
>all in one anyway. But different datums can be compressed differently.
>

I meant different toast values using different compression algorithm,
sorry for the confusion.

>
>> Another question is whether we'd actually want to include the code in
>> core directly, or use system libraries (and if some packagers might
>> decide to disable that, for whatever reason).
>
>I'd personally say we should have an included version, and a
>--with-system-... flag that uses the system one.
>

OK. I'd say to require a system library, but that's a minor detail.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services