Lu, Huayi
e6fa411af0
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
7.4 KiB
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.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | 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.