COMPILE Clause

13.13 COMPILE Clause

The compile clause explicitly recompiles a stored unit that has become invalid, thus eliminating the need for implicit runtime recompilation and preventing associated runtime compilation errors and performance overhead.

The COMPILE clause can appear in the following SQL statements:

Topics

Syntax

compile_clause ::=

Description of the illustration compile_clause.eps

compiler_parameters_clause ::=

Description of the illustration compiler_parameters_clause.eps

Semantics

compile_clause

COMPILE

Recompiles the PL/SQL unit, whether it is valid or invalid. The PL/SQL unit can be a library, package, package specification, package body, trigger, procedure, function, type, type specification, or type body.

First, if any of the objects upon which the unit depends are invalid, the database recompiles them.

The database also invalidates any local objects that depend upon the unit.

If the database recompiles the unit successfully, then the unit becomes valid. Otherwise, the database returns an error and the unit remains invalid. You can see the associated compiler error messages with the SQL*Plus command SHOW ERRORS.

During recompilation, the database drops all persistent compiler switch settings, retrieves them again from the session, and stores them after compilation. To avoid this process, specify the REUSE SETTINGS clause.

DEBUG

Has the same effect as PLSQL_OPTIMIZE_LEVEL=1—instructs the PL/SQL compiler to generate and store the code for use by the PL/SQL debugger. Oracle recommends using PLSQL_OPTIMIZE_LEVEL=1 instead of DEBUG.

PACKAGE

(Default) Recompiles both the package specification and (if it exists) the package body, whether they are valid or invalid. The recompilation of the package specification and body lead to the invalidation and recompilation of dependent objects as described for SPECIFICATION and BODY.

Restriction on PACKAGE

PACKAGE may only appear if compiling a package.

SPECIFICATION

Recompiles only the package or type specification, whether it is valid or invalid. You might want to recompile a package or type specification to check for compilation errors after modifying the specification.

When you recompile a specification, the database invalidates any local objects that depend on the specification, such as procedures that invoke procedures or functions in the package. The body of a package also depends on its specification. If you subsequently reference one of these dependent objects without first explicitly recompiling it, then the database recompiles it implicitly at run time.

Restriction on SPECIFICATION

SPECIFICATION may only appear if compiling a package or type specification.

BODY

Recompiles only the package or type body, whether it is valid or invalid. You might want to recompile a package or type body after modifying it. Recompiling a body does not invalidate objects that depend upon its specification.

When you recompile a package or type body, the database first recompiles the objects on which the body depends, if any of those objects are invalid. If the database recompiles the body successfully, then the body becomes valid.

Restriction on BODY

BODY may only appear if compiling a package or type body.

REUSE SETTINGS

Prevents Oracle Database from dropping and reacquiring compiler switch settings. With this clause, Oracle preserves the existing settings and uses them for the recompilation of any parameters for which values are not specified elsewhere in this statement.

See also DEFAULT COLLATION Clause compilation semantics.

compiler_parameters_clause

Specifies a value for a PL/SQL compilation parameter in Table 1-2. The compile-time value of each of these parameters is stored with the metadata of the PL/SQL unit being compiled.

You can specify each parameter only once in each statement. Each setting is valid only for the PL/SQL unit being compiled and does not affect other compilations in this session or system. To affect the entire session or system, you must set a value for the parameter using the ALTER SESSION or ALTER SYSTEM statement.

If you omit any parameter from this clause and you specify REUSE SETTINGS, then if a value was specified for the parameter in an earlier compilation of this PL/SQL unit, the database uses that earlier value. If you omit any parameter and either you do not specify REUSE SETTINGS or no value was specified for the parameter in an earlier compilation, then the database obtains the value for that parameter from the session environment.