Horton

pg11+: pg_ls_*dir LIMIT 1: temporary files .. not closed at end-of-transaction

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: pgsql-hackers@postgresql.org
Cc: Fabien COELHO <coelho@cri.ensmp.fr>, Alvaro Herrera <alvherre@2ndquadrant.com>, David Steele <david@pgmasters.net>, "Bossart, Nathan" <bossartn@amazon.com>, Thomas Munro <thomas.munro@gmail.com>
Date: 2020-03-08T17:31:03Z
Lists: pgsql-hackers 
While working on a patch, I noticed this pre-existing behavior, which seems to
be new since v11, maybe due to changes to SRF.

|postgres=# SELECT pg_ls_dir('.') LIMIT 1;
|WARNING:  1 temporary files and directories not closed at end-of-transaction
|pg_ls_dir | pg_dynshmem

|postgres=# SELECT pg_ls_waldir() LIMIT 1;
|WARNING:  1 temporary files and directories not closed at end-of-transaction
|-[ RECORD 1 ]+-------------------------------------------------------------
|pg_ls_waldir | (00000001000031920000007B,16777216,"2020-03-08 03:50:34-07")


Note, that doesn't happen with "SELECT * FROM".

I'm not sure what the solution is to that, but my patch was going to make it
worse rather than better for pg_ls_tmpdir.

-- 
Justin

Commits

  1. Teach pg_ls_dir_files() to ignore ENOENT failures from stat().

  2. Remove useless pfree()s at the ends of various ValuePerCall SRFs.

  3. Avoid holding a directory FD open across assorted SRF calls.

  4. Document pg_ls_*dir hiding of directories and special files

  5. Avoid holding a directory FD open across pg_ls_dir_files() calls.

  6. Adjust nodeFunctionscan.c to reset transient memory context between calls