Re: Polyphase merge is obsolete - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Polyphase merge is obsolete
Date
Msg-id CAM3SWZR4MQbXFuT1Q+TyRYSPbNVkHsMx+SfVQnHqFLi6tNQoAw@mail.gmail.com
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In response to Polyphase merge is obsolete  (Heikki Linnakangas <hlinnaka@iki.fi>)
List pgsql-hackers
On Wed, Oct 12, 2016 at 10:16 AM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> Let's switch over to a simple k-way balanced merge. Because it's simpler. If
> you're severely limited on memory, like when sorting 1GB of data with
> work_mem='1MB' or less, it's also slightly faster. I'm not too excited about
> the performance aspect, because in the typical case of a single-pass merge,
> there's no difference. But it would be worth changing on simplicity grounds,
> since we're mucking around in tuplesort.c anyway.

This analysis seems sound. I suppose we might as well simplify things
while we're at it.


-- 
Peter Geoghegan



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