Horton

Re: Use generation context to speed up tuplesorts

Ronan Dunklau <ronan.dunklau@aiven.io>

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From: Ronan Dunklau <ronan.dunklau@aiven.io>
To: David Rowley <dgrowleyml@gmail.com>, pgsql-hackers@lists.postgresql.org, Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Andres Freund <andres@anarazel.de>, Tomas Vondra <tv@fuzzy.cz>
Date: 2021-12-17T10:20:11Z
Lists: pgsql-hackers 
Le vendredi 17 décembre 2021, 09:08:06 CET Ronan Dunklau a écrit :
> It is my understanding that malloc will try to compact memory by moving it
> around. So the memory should be actually be released to the kernel at some
> point. In the meantime, malloc can reuse it for our next invocation (which
> can be in a different memory context on our side).

I've been told off-list this comment wasn't clear: I meant that it compacts 
*free* memory, consolidating into larger blocks that will eventually reach the 
threshold, and be released.

-- 
Ronan Dunklau

Commits

  1. Use Generation memory contexts to store tuples in sorts

  2. Adjust tuplesort API to have bitwise option flags

  3. Improve the generation memory allocator