Re: First draft of PG 19 release notes

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: shihao zhong <zhong950419(at)gmail(dot)com>
Cc: Bruce Momjian <bruce(at)momjian(dot)us>, PostgreSQL-development <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: First draft of PG 19 release notes
Date: 2026-10-17 04:13:00
Message-ID: 3382929.1792210380@sss.pgh.pa.us
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

shihao zhong <zhong950419(at)gmail(dot)com> writes:
> 4. The hash join change (1811f1af98f) can write outer rows with NULL
> keys to a temp file, even with one batch. A LEFT JOIN with 297000 NULL
> keys wrote 33 MB of temp files, 18.6 wrote none. With temp_file_limit at
> 1MB it fails.

I'm a bit skeptical about this one. The older code would have
put those rows into the primary hash table rather than a dedicated
tuplestore, but either way you risk having to dump them to disk.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message shihao zhong 2026-10-17 04:13:37 Re: [PG19] Wrong results from NOT NULL-based expression simplification
Previous Message shihao zhong 2026-10-17 04:03:07 Re: First draft of PG 19 release notes