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Re: NOT IN subquery optimization - Mailing list pgsql-hackers

From	Richard Guo
Subject	Re: NOT IN subquery optimization
Date	March 1, 2019 05:27:04
Msg-id	CAN_9JTweDc4uu2dDGB4tngoUc9Ouc7xOyGpd+s_Bz+5dAmprQg@mail.gmail.com Whole thread Raw
In response to	Re: NOT IN subquery optimization ("Li, Zheng" <zhelli@amazon.com>)
Responses	Re: NOT IN subquery optimization
List	pgsql-hackers

On Tue, Feb 26, 2019 at 6:51 AM Li, Zheng <zhelli@amazon.com> wrote:

Resend the patch with a whitespace removed so that "git apply patch" works directly.

Hi Zheng,

I have reviewed your patch. Good job except two issues I can find:

1. The patch would give wrong results when the inner side is empty. In this

case, the whole data from outer side should be in the outputs. But with the

patch, we will lose the NULLs from outer side.

2. Because of the new added predicate 'OR (var is NULL)', we cannot use hash

join or merge join to do the ANTI JOIN. Nested loop becomes the only choice,

which is low-efficency.

Thanks

Richard

From: Nikita Glukhov
Date: 01 March 2019, 05:24:39
Subject: Fix memleaks and error handling in jsonb_plpython

From: Michael Paquier
Date: 01 March 2019, 05:33:38
Subject: Tighten error control for OpenTransientFile/CloseTransientFile