Re: Lazy JIT IR code generation to increase JIT speed with partitions - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Lazy JIT IR code generation to increase JIT speed with partitions
Date
Msg-id 20220627153739.u7sb5i4kse2tgnjp@alvherre.pgsql
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In response to Re: Lazy JIT IR code generation to increase JIT speed with partitions  (Luc Vlaming <luc@swarm64.com>)
Responses Re: Lazy JIT IR code generation to increase JIT speed with partitions
List pgsql-hackers
On 2021-Jan-18, Luc Vlaming wrote:

> I would like this topic to somehow progress and was wondering what other
> benchmarks / tests would be needed to have some progress? I've so far
> provided benchmarks for small(ish) queries and some tpch numbers, assuming
> those would be enough.

Hi, some time ago I reported a case[1] where our JIT implementation does
a very poor job and perhaps the changes that you're making could explain
what is going on, and maybe even fix it:

[1] https://postgr.es/m/202111141706.wqq7xoyigwa2@alvherre.pgsql

The query for which I investigated the problem involved some pg_logical
metadata tables, so I didn't post it anywhere public; but the blog post
I found later contains a link to a query that shows the same symptoms,
and which is luckily still available online:
https://gist.github.com/saicitus/251ba20b211e9e73285af35e61b19580
I attach it here in case it goes missing sometime.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/

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