Horton

Re: 回复: An implementation of multi-key sort

Heikki Linnakangas <hlinnaka@iki.fi>

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From: Heikki Linnakangas <hlinnaka@iki.fi>
To: Wang Yao <yaowangm@outlook.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Cc: "interma@outlook.com" <interma@outlook.com>
Date: 2024-05-23T12:47:29Z
Lists: pgsql-hackers 
On 23/05/2024 15:39, Wang Yao wrote:
> No obvious perf regression is expected because PG will follow original
> qsort code path when mksort is disabled. For the case, the only extra
> cost is the check in tuplesort_sort_memtuples() to enter mksort code path.

And what about the case the mksort is enabled, but it's not effective 
because all leading keys are different?

-- 
Heikki Linnakangas
Neon (https://neon.tech)