ALTER DIMENSION

ALTER DIMENSION

Purpose

Use the ALTER DIMENSION statement to change the hierarchical relationships or dimension attributes of a dimension.

See Also: CREATE DIMENSION on page 13-43 for more information on dimensions

Prerequisites

The dimension must be in your schema or you must have the ALTER ANY

DIMENSION system privilege to use this statement.

A dimension is always altered under the rights of the owner.

Syntax

alter_dimension::=

level_clause ADD hierarchy_clause

attribute_clause

RESTRICT

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ALTER DIMENSION

level_clause::=

hierarchy_clause::=

Semantics

The following keywords, parameters, and clauses have meaning unique to ALTER DIMENSION. Keywords, parameters, and clauses that do not appear here have the same functionality that they have in the CREATE DIMENSION statement.

See Also: CREATE DIMENSION on page 13-43

schema

Specify the schema of the dimension you want to modify. If you do not specify schema, Oracle assumes the dimension is in your own schema.

SQL Statements: ALTER CLUSTER to ALTER SEQUENCE 9-57

ALTER DIMENSION

dimension

Specify the name of the dimension. This dimension must already exist.

ADD

The ADD clauses let you add a level, hierarchy, or attribute to the dimension. Adding one of these elements does not invalidate any existing materialized view.

Oracle processes ADD LEVEL clauses prior to any other ADD clauses.

DROP

The DROP clauses let you drop a level, hierarchy, or attribute from the dimension. Any level, hierarchy, or attribute you specify must already exist.

Restriction on DROP If any attributes or hierarchies reference a level, you cannot drop the level until you either drop all the referencing attributes and hierarchies or specify CASCADE.

CASCADE Specify CASCADE if you want Oracle to drop any attributes or hierarchies that reference the level, along with the level itself.

RESTRICT Specify RESTRICT if you want to prevent Oracle from dropping a level that is referenced by any attributes or hierarchies. This is the default.

COMPILE

Specify COMPILE to explicitly recompile an invalidated dimension. Oracle automatically compiles a dimension when you issue an ADD clause or DROP clause. However, if you alter an object referenced by the dimension (for example, if you drop and then re-create a table referenced in the dimension), the dimension will be invalidated, and you must recompile it explicitly.

Example

Modifying a Dimension: Examples The following examples modify the customers_dim dimension in the sample schema sh:

ALTER DIMENSION customers_dim

DROP ATTRIBUTE country;

ALTER DIMENSION customers_dim

ADD LEVEL zone IS customers.cust_postal_code

ADD ATTRIBUTE zone DETERMINES (cust_city);

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ALTER FUNCTION

ALTER FUNCTION

Purpose

Use the ALTER FUNCTION statement to recompile an invalid standalone stored function. Explicit recompilation eliminates the need for implicit run-time recompilation and prevents associated run-time compilation errors and performance overhead.

The ALTER FUNCTION statement is similar to ALTER PROCEDURE on page 9-124. For information on how Oracle recompiles functions and procedures, see Oracle9i Database Concepts.

Note: This statement does not change the declaration or definition of an existing function. To redeclare or redefine a function, use the CREATE FUNCTION statement with the OR REPLACE clause; see CREATE FUNCTION on page 13-52.

Prerequisites

The function must be in your own schema or you must have ALTER ANY

PROCEDURE system privilege.

Syntax

alter_function::=

Semantics

schema

Specify the schema containing the function. If you omit schema, Oracle assumes the function is in your own schema.

function

Specify the name of the function to be recompiled.

SQL Statements: ALTER CLUSTER to ALTER SEQUENCE 9-59

ALTER FUNCTION

COMPILE

Specify COMPILE to cause Oracle to recompile the function. The COMPILE keyword is required. If Oracle does not compile the function successfully, you can see the associated compiler error messages with the SQL*Plus command SHOW ERRORS.

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

DEBUG

Specify DEBUG to instruct the PL/SQL compiler to generate and store the code for use by the PL/SQL debugger.

REUSE SETTINGS

Specify REUSE SETTINGS to prevent Oracle from dropping and reacquiring compiler switch settings. With this clause, Oracle preserves the existing settings and uses them for the recompilation.

If you specify both DEBUG and REUSE SETTINGS, Oracle sets the persistently stored value of the PLSQL_COMPILER_FLAGS parameter to INTERPRETED, DEBUG. No other compiler switch values are changed.

See Also: PL/SQL User’s Guide and Reference and Oracle9i Application Developer’s Guide - Fundamentals for more information on the interaction of the PLSQL_COMPILER_FLAGS parameter with the COMPILE clause

Example

Recompiling a Function: Example To explicitly recompile the function get_bal owned by the sample user oe, issue the following statement:

ALTER FUNCTION oe.get_bal

COMPILE;

If Oracle encounters no compilation errors while recompiling get_bal, get_bal becomes valid. Oracle can subsequently execute it without recompiling it at run time. If recompiling get_bal results in compilation errors, Oracle returns an error, and get_bal remains invalid.

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ALTER FUNCTION

Oracle also invalidates all objects that depend upon get_bal. If you subsequently reference one of these objects without explicitly recompiling it first, Oracle recompiles it implicitly at run time.

SQL Statements: ALTER CLUSTER to ALTER SEQUENCE 9-61