The LIMIT method returns the maximum number of elements that a collection can contain. If a collection does not have a maximum number of elements, the LIMIT method returns NULL.
Applicability
This topic applies only to OceanBase Database Enterprise Edition. OceanBase Database Community Edition does not support this feature.
Only varrays have a maximum size.
Here is an example:
obclient> DECLARE
TYPE asa_ty IS TABLE OF INTEGER INDEX BY PLS_INTEGER;
asa asa_ty; -- Associative array
TYPE vaa_ty IS VARRAY(5) OF INTEGER;
vaa vaa_ty := vaa_ty(2,4,6); -- Varray
TYPE nested_ty IS TABLE OF INTEGER;
ntt nested_ty := nested_ty(1,3,5,7); -- Nested table
BEGIN
asa(1):=2; asa(2):=4; asa(3):=6; asa(4):= 8; asa(5):= 10;
DBMS_OUTPUT.PUT('asa.COUNT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(asa.COUNT), 'NULL'));
DBMS_OUTPUT.PUT('asa.LIMIT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(asa.LIMIT), 'NULL'));
DBMS_OUTPUT.PUT('vaa.COUNT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(vaa.COUNT), 'NULL'));
DBMS_OUTPUT.PUT('vaa.LIMIT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(vaa.LIMIT), 'NULL'));
DBMS_OUTPUT.PUT('ntt.COUNT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(ntt.COUNT), 'NULL'));
DBMS_OUTPUT.PUT('ntt.LIMIT = ');
DBMS_OUTPUT.PUT_LINE(NVL(TO_CHAR(ntt.LIMIT), 'NULL'));
END;
/
Query OK, 0 rows affected
asa.COUNT = 5
asa.LIMIT = NULL
vaa.COUNT = 3
vaa.LIMIT = 5
ntt.COUNT = 4
ntt.LIMIT = NULL
This example creates an associative array with five elements, a varray with three elements, and a nested table with four elements. It then outputs the values of LIMIT and COUNT.