System Function Checking Functions¶
pv_builtin_functions()¶
Description: Queries information about system functions.
Return type: record
pg_get_functiondef(func_oid)¶
Description: Gets definition of a function.
Return type: text
func_oid is the OID of the function, which can be queried in the PG_PROC system catalog.
Example: Query the OID and definition of the justify_days function.
SELECT oid FROM pg_proc WHERE proname ='justify_days';
oid
------
1295
(1 row)
SELECT * FROM pg_get_functiondef(1295);
headerlines | definition
-------------+--------------------------------------------------------------
4 | CREATE OR REPLACE FUNCTION pg_catalog.justify_days(interval)+
| RETURNS interval +
| LANGUAGE internal +
| IMMUTABLE STRICT NOT FENCED NOT SHIPPABLE +
| AS $function$interval_justify_days$function$ +
|
(1 row)
pg_get_function_arguments(func_oid)¶
Description: Gets argument list of function's definition (with default values).
Return type: text
Note: pg_get_function_arguments returns the argument list of a function, in the form it would need to appear in within CREATE FUNCTION.
pg_get_function_identity_arguments(func_oid)¶
Description: Gets argument list to identify a function (without default values).
Return type: text
Note: pg_get_function_identity_arguments returns the argument list necessary to identify a function, in the form it would need to appear in within ALTER FUNCTION. This form omits default values.
pg_get_function_result(func_oid)¶
Description: Gets RETURNS clause for function.
Return type: text
Note: pg_get_function_result returns the appropriate RETURNS clause for the function.