14.58 RESULT_CACHE Clause

Indicates to store the function results into the server result cache.

The RESULT_CACHE clause can appear in the following SQL statements:

• CREATE FUNCTION Statement

• CREATE TYPE BODY Statement

Topics

• Syntax

• Semantics

• Examples

• Related Topics

Syntax

result_cache_clause ::=

Description of the illustration result_cache_clause.eps

Semantics

result_cache_clause

result_cache_clause can appear only once in the function.

RESULT_CACHE

To make a function result-cached, include the RESULT_CACHE clause in the function definition. If you declare the function before defining it, you must also include the RESULT_CACHE option in the function declaration.

Restriction on RESULT_CACHE

• RESULT_CACHE is disallowed on functions with OUT or IN OUT parameters.

• RESULT_CACHE is disallowed on functions with IN or RETURN parameter of (or containing) these types:

  • BLOB

  • CLOB

  • NCLOB

  • REF CURSOR

  • Collection

  • Object

  • Record or PL/SQL collection that contains an unsupported return type

• RESULT_CACHE is disallowed on function in an anonymous block.

• RESULT_CACHE is disallowed on pipelined table function, nested function and SQL macro.

RELIES_ON

Specifies the data sources on which the results of the function depend. Each data_source is the name of either a database table or view.

Note:

• This clause is deprecated. As of Oracle Database 12c, the database detects all data sources that are queried while a result-cached function is running, and RELIES_ON clause does nothing.

• You cannot use RELIES_ON clause in a function declared in an anonymous block.

Examples

• Examples of Result-Cached Functions

Related Topics

In this chapter:

• Function Declaration and Definition

In other chapters:

• PL/SQL Function Result Cache

In other books:

• Oracle Database Performance Tuning Guide