Re: BUG #19040: Memory leak in hashed subplan node due to missing hashtempcxt reset

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: feichanghong <feichanghong@qq.com>

Cc: "李海洋(陌痕)" <mohen.lhy@alibaba-inc.com>, ocean_li_996 <ocean_li_996@163.com>, "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>

Date: 2025-09-09T03:05:09Z

Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Eliminate duplicative hashtempcxt in nodeSubplan.c.
- bdc6cfcd12f5 19 (unreleased) landed
Fix memory leakage in nodeSubplan.c.
- e1da9c072106 16.11 landed
- bc865ff6d1f0 18.0 landed
- abdeacdb0920 19 (unreleased) landed
- 8b6c29afd125 13.23 landed
- 862980f924ff 17.7 landed
- 5eab9b0a473e 14.20 landed
- 5ac973892b09 15.15 landed
Do execGrouping.c via expression eval machinery, take two.
- bf6c614a2f2c 11.0 cited
Fix potential failure when hashing the output of a subplan that produces
- 133924e13e00 9.1.0 cited

feichanghong <feichanghong@qq.com> writes:
> For v04-0002, I checked the commit history, and before commit 133924e1,
> buildSubPlanHash was using ecxt_per_tuple_memory. It seems that the
> "Subplan HashTable Temp Context" was introduced in order to fix a certain bug.

It was a different ExprContext's ecxt_per_tuple_memory, though.
This one is owned locally by the TupleHashTable.

			regards, tom lane