What ORA-06512: At Line Means in Oracle and How to Find the Error

ORA-06512 is not an error of its own. It is a line of the error stack that says where an error passed through PL/SQL code: which program unit, and which line. The real error is the first line of the stack, above the ORA-06512 lines. To fix the problem, read that first error, then follow the ORA-06512 lines to the code that raised it.

See It in an Error Stack

One procedure checks a quantity and raises an error; another calls it:

Example:

create or replace procedure demo_check_qty (p_qty number) is
begin
  if p_qty > 10 then
    raise_application_error(-20001, 'At most 10 seats per order');
  end if;
end;
/
create or replace procedure demo_place_order (p_qty number) is
begin
  demo_check_qty(p_qty);
end;
/
exec demo_place_order(12)

Output:

Procedure DEMO_CHECK_QTY compiled

Procedure DEMO_PLACE_ORDER compiled

BEGIN demo_place_order(12); END;
*
ERROR at line 1:
ORA-20001: At most 10 seats per order
ORA-06512: at "NIMBUS.DEMO_CHECK_QTY", line 4
ORA-06512: at "NIMBUS.DEMO_PLACE_ORDER", line 3
ORA-06512: at line 1

• ORA-20001 is the actual error, the one to fix.
• The ORA-06512 lines go from where it was raised, line 4 of DEMO_CHECK_QTY, outward to the caller, line 3 of DEMO_PLACE_ORDER, and to line 1 of the anonymous block.
• For an anonymous block, the line number counts from its first line, DECLARE or BEGIN.

Find the Line in the Source

Example:

-- the line each ORA-06512 points to
select name, line, text
from   user_source
where  (name = 'DEMO_CHECK_QTY' and line = 4)
or     (name = 'DEMO_PLACE_ORDER' and line = 3)
order  by name desc;

Output:

NAME                   LINE TEXT
___________________ _______ _____________________________________________________________________
DEMO_PLACE_ORDER          3   demo_check_qty(p_qty);
DEMO_CHECK_QTY            4     raise_application_error(-20001, 'At most 10 seats per order');

Keep the Line Numbers When You Handle Errors

An exception handler that logs SQLERRM alone loses the location. DBMS_UTILITY.FORMAT_ERROR_BACKTRACE returns the ORA-06512 lines:

Example:

set serveroutput on
begin
  demo_place_order(12);
exception
  when others then
    dbms_output.put_line(sqlerrm);
    dbms_output.put_line(dbms_utility.format_error_backtrace);
end;
/

Output:

ORA-20001: At most 10 seats per order
ORA-06512: at "NIMBUS.DEMO_CHECK_QTY", line 4
ORA-06512: at "NIMBUS.DEMO_PLACE_ORDER", line 3
ORA-06512: at line 2

PL/SQL procedure successfully completed.

Things to Know

• A handler that catches and raises a new error, for example with RAISE_APPLICATION_ERROR, starts a new stack at the handler; pass TRUE as its third argument to keep the original errors.
• An ORA-06512 line without a program name, such as "at line 1", refers to the anonymous block that was run.
• ORA-06512 lines also appear below errors raised by Oracle, such as ORA-01403 or ORA-01476.

Related Guides

• Error Handling with Dbms_utility.format_error_backtrace
• How to Read the Call Stack with UTL_CALL_STACK

Conclusion

ORA-06512 shows where an error traveled through PL/SQL. Fix the error at the top of the stack, use the first ORA-06512 line to find where it was raised, and log FORMAT_ERROR_BACKTRACE in handlers so the location is not lost.