|Oracle® Database PL/SQL Language Reference
12c Release 1 (12.1)
|PDF · Mobi · ePub|
For instructions for reading the syntax diagrams in this chapter, see Oracle Database SQL Language Reference.
Each of these
CREATE statements has an optional
REPLACE clause. Specify
REPLACE to re-create an existing PL/SQL unit—that is, to change its declaration or definition without dropping it, re-creating it, and regranting object privileges previously granted on it. If you redefine a PL/SQL unit, the database recompiles it.
REPLACEstatement does not issue a warning before replacing the existing PL/SQL unit.
None of these
CREATE statements can appear in a PL/SQL block.
Reasons to use an
ALTER statement are:
To explicitly recompile a stored unit that has become invalid, thus eliminating the need for implicit runtime recompilation and preventing associated runtime compilation errors and performance overhead.
To recompile a stored unit with different compilation parameters.
For information about compilation parameters, see "PL/SQL Units and Compilation Parameters".
To enable or disable a trigger.
To specify the
NONEDITIONABLE property of a stored unit whose schema object type is not yet editionable in its schema.
For information about editioned and noneditioned objects, see Oracle Database Development Guide.
TYPE statement has additional uses. For details, see "ALTER TYPE Statement".
To drop an existing PL/SQL unit from the database, use one of these SQL statements: