Hello guys.

I'm facing the following problem which seems to me a bug. Postgres version used - 13.7

 

1) Connection1:

create or replace function test_fn() returns text as $$

begin

  return 'version1';

end;

$$ language plpgsql;

 

2) Connection2:

begin;

select test_fn();

 test_fn

---------

 version1

(1 row)

 

3) Connection1:

create or replace function test_fn() returns text as $$

begin

  return 'version2';

end;

$$ language plpgsql;

 

4) Connection2:

select test_fn();

 test_fn

---------

 version1

(1 row)

 

So the question is why Connection2 does not see updated version of test_fn? I've looked at source code and found that system cache invalidations (PROCOID cache in this case) occurs in AcceptInvalidationMessages() call chain. This function is called in a plenty of places but not when we call function in a running transaction as in the example. My thought is that AcceptInvalidationMessages() should be called in xact.c --> StartTransactionCommand() for TBLOCK_INPROGRESS, TBLOCK_IMPLICIT_INPROGRESS, TBLOCK_SUBINPROGRESS cases. Am I right or is it not even a bug?