Message-ID: <5539491C.6040405@BlueTreble.com>
Date: Thu, 23 Apr 2015 14:33:48 -0500
From: Jim Nasby <Jim.Nasby@BlueTreble.com>
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To: Petr Jelinek <petr@2ndquadrant.com>, Andres Freund <andres@anarazel.de>,
 <hlinnaka@iki.fi>, Robert Haas <robertmhaas@gmail.com>
CC: Bruce Momjian <bruce@momjian.us>, Sawada Masahiko <sawada.mshk@gmail.com>,
 Greg Stark <stark@mit.edu>, PostgreSQL-development
 <pgsql-hackers@postgresql.org>, Jeff Janes <jeff.janes@gmail.com>
Subject: Re: Reducing tuple overhead
References: <20150423162429.GG3055@alap3.anarazel.de>
 <553921B1.7080204@2ndquadrant.com>
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On 4/23/15 11:45 AM, Petr Jelinek wrote:
> On 23/04/15 18:24, Andres Freund wrote:
>> Whether that's feasible complexity wise is debatable, but it's certainly
>> possible.
>>
>>
>> I do wonder what, in realistic cases, is actually the bigger contributor
>> to the overhead. The tuple header or the padding we liberally add in
>> many cases...
>>
>
> The logical ordering patch + auto optimizations of column layout on
> table creation/rewrite might help partially there.
>
> But what seems to be clear is that we need more in depth analysis of
> what really contributes most to the tuple size in various use-cases and
> then we can debate what we can do about it.

Also, what Robert posted was that while we started at something like 
15%-30% larger, we ended the test at 80% larger. That makes me think 
that the bigger win is not in reducing tuple size but tackling bloat.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com


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