BUG #16405: Exception P0004 not caught in EXCEPTION WHEN OTHERS
The following bug has been logged on the website:
Bug reference: 16405
Logged by: Jacob Crell
Email address: jacobcrell@gmail.com
PostgreSQL version: 10.0
Operating system: AWS Aurora
Description:
Create below function to return assertion failue:
CREATE OR REPLACE FUNCTION assert_fail()
RETURNS void
LANGUAGE plpgsql
AS $function$
BEGIN
ASSERT FALSE, 'Assertion Failed';
END;
$function$;
Create this function to call above function and catch error:
CREATE OR REPLACE FUNCTION catch_assert_fail()
RETURNS text
LANGUAGE plpgsql
AS $function$
BEGIN
SELECT * FROM meta.assert_fail();
RETURN 'Function Finished';
EXCEPTION WHEN OTHERS THEN
RETURN 'Hit the Other exception block';
END;
$function$;
Run below to call function
SELECT * FROM catch_assert_fail()
Excepted Behavior: P0004 exception is caught in EXCEPTION WHEN OTHERS,
function returns text 'Hit the Other exception block'.
Actual Behavior: P0004 exception is raised and remains uncaught.
PG Bug reporting form <noreply@postgresql.org> writes:
Excepted Behavior: P0004 exception is caught in EXCEPTION WHEN OTHERS,
function returns text 'Hit the Other exception block'.
Actual Behavior: P0004 exception is raised and remains uncaught.
That's intentional, per the documentation [1]https://www.postgresql.org/docs/current/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING:
The special condition name OTHERS matches every error type except
QUERY_CANCELED and ASSERT_FAILURE. (It is possible, but often unwise,
to trap those two error types by name.)
regards, tom lane
[1]: https://www.postgresql.org/docs/current/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING
Thanks for the reply Tom! Makes sense.
On Thu, Apr 30, 2020 at 12:04 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Show quoted text
PG Bug reporting form <noreply@postgresql.org> writes:
Excepted Behavior: P0004 exception is caught in EXCEPTION WHEN OTHERS,
function returns text 'Hit the Other exception block'.
Actual Behavior: P0004 exception is raised and remains uncaught.That's intentional, per the documentation [1]:
The special condition name OTHERS matches every error type except
QUERY_CANCELED and ASSERT_FAILURE. (It is possible, but often unwise,
to trap those two error types by name.)regards, tom lane
[1]
https://www.postgresql.org/docs/current/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING