How to Fix ORA-06533: Subscript Beyond Count in Oracle

ORA-06533 is raised when PL/SQL code reads or writes a nested table or varray element whose index is greater than the collection's current number of elements. These collections grow only through EXTEND, so element 3 of a two-element collection does not exist yet, even for assignment. The predefined exception is SUBSCRIPT_BEYOND_COUNT. Extend the collection before assigning, and check COUNT or EXISTS before reading.

Reproduce the Error

Example:

declare
  type num_list is table of number;
  v_list num_list := num_list(10, 20);
begin
  v_list(3) := 30;
end;
/
declare
  type num_list is table of number;
  v_list num_list := num_list(10, 20);
begin
  dbms_output.put_line(v_list(3));
end;
/

Output:

declare
*
ERROR at line 1:
ORA-06533: Subscript beyond count
ORA-06512: at line 5

declare
*
ERROR at line 1:
ORA-06533: Subscript beyond count
ORA-06512: at line 5

Writing and reading element 3 both fail, because the collection has two elements.

Fix: EXTEND First, and Check Before Reading

Example:

set serveroutput on
declare
  type num_list is table of number;
  v_list num_list := num_list(10, 20);
begin
  v_list.extend;                 -- make room for element 3
  v_list(3) := 30;
  for i in 1 .. v_list.count loop
    dbms_output.put_line(i || ': ' || v_list(i));
  end loop;
  if v_list.exists(4) then
    dbms_output.put_line(v_list(4));
  else
    dbms_output.put_line('No element 4');
  end if;
end;
/

Output:

1: 10
2: 20
3: 30
No element 4

PL/SQL procedure successfully completed.

EXTEND adds element 3, the loop stays within 1 to COUNT, and EXISTS tests an index without raising an error.

Associative Arrays Behave Differently

An associative array has no count limit: any index can be assigned, and reading a missing one raises NO_DATA_FOUND:

Example:

-- an associative array has no count limit: a missing key raises NO_DATA_FOUND instead
declare
  type num_map is table of number index by pls_integer;
  v_map num_map;
begin
  v_map(1) := 10;
  v_map(100) := 30;              -- allowed, no EXTEND needed
  dbms_output.put_line(v_map(2));
end;
/

Output:

declare
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 7

Things to Know

• EXTEND(n) adds n elements at once, which is faster than one EXTEND per element in a loop.
• After DELETE of single elements, a nested table has gaps; loop with FIRST and NEXT instead of 1 to COUNT.

Related Guides

• How to Use Associative Arrays in PL/SQL
• How to Fix ORA-06532: Subscript Outside of Limit in Oracle

Conclusion

ORA-06533 means an index above the collection's COUNT. Call EXTEND before assigning new elements, loop within COUNT, and use EXISTS to test an index safely.