Hi!

Thanks for response.

I do not know whether this is correct to throw error when we can not do it.
'temp_file_limit' is enforced for actually created files and not on BufFile, so
if we can create one without it's associated file, then I see here no problems.

And this must be true for both normal and inter-xact, because in that case
owner backend is the only who can work with the file, so there is no need
to forcibly create disk file.

Hello

I think there is an issue with this patch: you are not taking into account a 
inter-transaction BufFile.

If a BufFile is created with isInterXact set to true, BufFileClose does not 
flush data and this looks wrong.

You can test this with the following extension 
https://github.com/pierreforstmann/buffile .

With PostgreSQL 20devdel, I get:
--
-- Test BufFileClose() flushing behavior.
--
CREATE EXTENSION buffile;
-- A regular temporary BufFile should not be flushed by BufFileClose().
--
-- With temp_file_limit = 0, a physical write must fail.  Therefore
-- false means that BufFileClose() did not attempt the write.
SET temp_file_limit = 0;
SELECT test_buffile_temp(false);
INFO:  BufFileClose has not flushed data
  test_buffile_temp
-------------------
  f
(1 row)

-- An inter-transaction BufFile must still be flushed by BufFileClose().
--
-- Therefore the physical write should fail with temp_file_limit = 0.
SELECT test_buffile_temp(true);
INFO:  BufFileClose has not flushed data
  test_buffile_temp
-------------------
  f
(1 row)

RESET temp_file_limit;
-- A FileSet BufFile must also be flushed by BufFileClose(), because
-- another opener must be able to see its contents.
SELECT test_buffile_fileset();
INFO:  BufFileClose has flushed data
  test_buffile_fileset
----------------------
  t
(1 row)


Regards
Pierre Forstmann

---
Sergey Soloviev

TantorLabs: https://tantorlabs.com




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