Oracle ORA-06553 Error: Causes and Solutions Complete Guide

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ORA-06553: PLS Error String – Causes, Fixes, and Prevention

ORA-06553 is an Oracle error that wraps internal PL/SQL compiler (PLS) errors occurring during the compilation or execution of PL/SQL blocks, stored procedures, functions, or packages. The "error string" portion of the message contains the specific PLS error detail, such as PLS-00306 or similar codes. This error most commonly appears alongside ORA-06550 and typically points to a mismatch in parameters, syntax issues, or invalid PL/SQL object states.

Top 3 Causes

1. Bind Variable Mismatch in Dynamic SQL

Using EXECUTE IMMEDIATE or DBMS_SQL with incorrect bind variable counts or types is the most frequent cause of ORA-06553. The PL/SQL runtime cannot match the declared bind placeholders to the supplied variables, triggering an internal PLS error.

-- WRONG: Three placeholders, only two bind variables supplied
DECLARE
  v_result NUMBER;
  v_sql    VARCHAR2(200);
BEGIN
  v_sql := 'BEGIN :1 := get_value(:2, :3); END;';
  EXECUTE IMMEDIATE v_sql USING OUT v_result, 42;
  -- Missing third bind variable -> ORA-06553
END;
/

-- CORRECT: All placeholders matched with proper mode and type
DECLARE
  v_result NUMBER;
  v_sql    VARCHAR2(200);
BEGIN
  v_sql := 'BEGIN :1 := get_value(:2, :3); END;';
  EXECUTE IMMEDIATE v_sql USING OUT v_result, IN 42, IN 'ACTIVE';
  DBMS_OUTPUT.PUT_LINE('Result: ' || v_result);
END;
/

2. Invalid or Uncompiled Stored PL/SQL Objects

After schema migrations, Oracle version upgrades, or dependency changes, stored procedures and functions can become INVALID. Calling them triggers ORA-06553 wrapped around the underlying PLS compilation error.

-- Check for invalid objects in your schema
SELECT object_name, object_type, status
FROM   user_objects
WHERE  status = 'INVALID'
ORDER  BY object_type, object_name;

-- Recompile a specific procedure
ALTER PROCEDURE my_procedure COMPILE;

-- Recompile an entire schema using UTL_RECOMP
EXEC UTL_RECOMP.RECOMP_SERIAL('MY_SCHEMA');

-- View detailed compilation errors after recompile attempt
SELECT line, position, text
FROM   user_errors
WHERE  name = 'MY_PROCEDURE'
ORDER  BY sequence;

3. Wrong Parameter Modes or Signatures in Procedure Calls

Calling a stored procedure or function with the wrong parameter modes (IN, OUT, IN OUT) or data types causes the PL/SQL compiler to raise an internal PLS error, which surfaces as ORA-06553.

-- Procedure defined with OUT parameter
CREATE OR REPLACE PROCEDURE get_employee_name (
  p_emp_id  IN  NUMBER,
  p_emp_name OUT VARCHAR2
) IS
BEGIN
  SELECT first_name || ' ' || last_name
  INTO   p_emp_name
  FROM   employees
  WHERE  employee_id = p_emp_id;
END get_employee_name;
/

-- WRONG: Passing a literal where OUT is expected
-- EXEC get_employee_name(101, 'John');  -- Will cause ORA-06553

-- CORRECT: Using a variable for the OUT parameter
DECLARE
  v_name VARCHAR2(100);
BEGIN
  get_employee_name(101, v_name);
  DBMS_OUTPUT.PUT_LINE('Employee: ' || v_name);
END;
/

Quick Fix Solutions

Read the full error stack – ORA-06553 is a wrapper. Always read the accompanying PLS error code in the message string for the root cause.
Query USER_ERRORS immediately after a failed compile:

SELECT name, type, line, position, text
FROM   user_errors
WHERE  name = UPPER('your_object_name')
ORDER  BY sequence;

Recompile invalid objects using ALTER ... COMPILE or UTL_RECOMP as shown above.
Validate dynamic SQL before execution using DBMS_SQL.PARSE to catch syntax errors early rather than at runtime.

Prevention Tips

Always verify compilations in your deployment pipeline. After deploying any PL/SQL object, run a script that checks USER_ERRORS and fails the deployment if any errors are found. This catches ORA-06553-causing issues before they hit production.
Minimize dynamic SQL and document bind variables explicitly. When dynamic SQL is unavoidable, keep a clear record of each placeholder's position, data type, and mode. Consider wrapping dynamic SQL calls inside utility procedures that enforce parameter validation, reducing the risk of bind variable mismatches that lead to ORA-06553 at runtime.

Related Errors

Error Code	Description
`ORA-06550`	PL/SQL compilation error with line/column info – almost always accompanies ORA-06553
`PLS-00306`	Wrong number or types of arguments in a call
`ORA-04068`	Existing state of packages has been discarded after recompilation
`ORA-06512`	Stack trace information pointing to the error location

📖 Want a more detailed guide?
Check out the full in-depth version (Korean) on oraerror.com — includes detailed analysis, additional SQL examples, and prevention tips.

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