When SQL*Plus Reports an Error but the PL/SQL Package Is Actually Valid

I encountered an interesting situation while deploying an Oracle PL/SQL package through SQL*Plus. The script appeared to fail with:

SP2-0341:
line overflow during variable substitution
(>3000 characters at line ...)

At first, this looked like a PL/SQL compilation failure. It wasn't.

What Happened

SQL> @load_application_pkg.sql

Package created.

SP2-0341:
line overflow during variable substitution
(>3000 characters at line 667)

The confusing part was that SQL*Plus first reported Package created. and then displayed an error. That raises an important question: did Oracle reject the package, or did the SQL*Plus client encounter a problem while processing some part of the script?

Oracle Errors vs. SQL*Plus Errors

SP2-xxxxx  → SQL*Plus
ORA-xxxxx  → Oracle Database
PLS-xxxxx  → PL/SQL compiler

Because the error began with SP2, my first step was not to rewrite the PL/SQL source. Instead, I checked the actual database object.

Check the Object in the Database

SELECT object_name,
       object_type,
       status
FROM user_objects
WHERE object_name = 'LOAD_APPLICATION_PKG';

I could also explicitly compile the package and body:

ALTER PACKAGE load_application_pkg COMPILE;
ALTER PACKAGE load_application_pkg COMPILE BODY;

and inspect compilation errors:

SHOW ERRORS PACKAGE load_application_pkg;
SHOW ERRORS PACKAGE BODY load_application_pkg;

For a queryable view of errors:

SELECT line,
       position,
       text
FROM user_errors
WHERE name = 'LOAD_APPLICATION_PKG'
ORDER BY sequence;

If the package is VALID and Oracle reports no compilation errors, the PL/SQL object itself compiled successfully.

Why SET DEFINE OFF Is Not Always the Answer

Because the message mentioned variable substitution, a natural test was:

SET DEFINE OFF

This disables SQL*Plus substitution variables such as &variable. However, when the same error persists, simply disabling substitution is not enough to explain the problem.

Think in Layers

Shell
  ↓
SQL*Plus
  ↓
Oracle SQL parser
  ↓
PL/SQL compiler
  ↓
Database object