CREATE INDEXTYPE

Purpose

Use the CREATE INDEXTYPE statement to create an indextype, which is an object that specifies the routines that manage a domain (application-specific) index. Indextypes reside in the same namespace as tables, views, and other schema objects. This statement binds the indextype name to an implementation type, which in turn specifies and refers to user-defined index functions and procedures that implement the indextype.

Prerequisites

To create an indextype in your own schema, you must have the CREATE INDEXTYPE system privilege. To create an indextype in another schema, you must have the CREATE ANY INDEXTYPE system privilege. In either case, you must have the EXECUTE object privilege on the implementation type and the supported operators.

An indextype supports one or more operators, so before creating an indextype, you must first design the operator or operators to be supported and provide functional implementation for those operators.

Syntax

create_indextype::=

using_type_clause::=

array_DML_clause ::=

storage_table_clause::=

Semantics

schema

Specify the name of the schema in which the indextype resides. If you omit schema, then Oracle Database creates the indextype in your own schema.

indextype

Specify the name of the indextype to be created.

FOR Clause

Use the FOR clause to specify the list of operators supported by the indextype.

• For schema, specify the schema containing the operator. If you omit schema, then Oracle assumes the operator is in your own schema.

• For operator, specify the name of the operator supported by the indextype.

  All the operators listed in this clause must be valid operators.

• For parameter_type, list the types of parameters to the operator.

using_type_clause

The USING clause lets you specify the type that provides the implementation for the new indextype.

For implementation_type, specify the name of the type that implements the appropriate Oracle Data Cartridge Interface (ODCI).

• You must specify a valid type that implements the routines in the ODCI.

• The implementation type must reside in the same schema as the indextype.

WITH LOCAL PARTITION

Use this clause to indicate that the indextype can be used to create local domain indexes on range-, list-, hash-, and interval-partitioned tables. You use this clause in combination with the storage_table_clause in several ways (see storage_table_clause).

• The recommended method is to specify WITH LOCAL PARTITION WITH SYSTEM MANAGED STORAGE TABLES. This combination uses system-managed storage tables, which are the preferred storage management, and lets you create local domain indexes on range-, list-, hash-, and interval-partitioned tables. In this case the RANGE keyword is optional and ignored, because it is no longer needed if you specify WITH LOCAL PARTITION WITH SYSTEM MANAGED STORAGE TABLES.

• You can specify WITH LOCAL RANGE PARTITION (including the RANGE keyword) and omit the storage_table clause. Local domain indexes on range-partitioned tables are supported with user-managed storage tables for backward compatibility. Oracle does not recommend this combination because it uses the less efficient user-managed storage tables.

If you omit this clause entirely, then you cannot subsequently use this indextype to create a local domain index on a range, list-, hash-, or interval-partitioned table.

storage_table_clause

Use this clause to specify how storage tables and partition maintenance operations for indexes built on this indextype are managed:

• Specify WITH SYSTEM MANAGED STORAGE TABLES to indicate that the storage of statistics data is to be managed by the system. The type you specify in statistics_type should be storing the statistics related information in tables that are maintained by the system. Also, the indextype you specify must already have been created or altered to support the WITH SYSTEM MANAGED STORAGE TABLES clause.

• Specify WITH USER MANAGED STORAGE TABLES to indicate that the tables that store the user-defined statistics will be managed by the user. This is the default behavior.

array_DML_clause

Use this clause to let the indextype support the array interface for the ODCIIndexInsert method.

type and varray_type If the data type of the column to be indexed is a user-defined object type, then you must specify this clause to identify the varray varray_type that Oracle should use to hold column values of type. If the indextype supports a list of types, then you can specify a corresponding list of varray types. If you omit schema for either type or varray_type, then Oracle assumes the type is in your own schema.

If the data type of the column to be indexed is a built-in system type, then any varray type specified for the indextype takes precedence over the ODCI types defined by the system.

Examples

Creating an Indextype: Example The following statement creates an indextype named position_indextype and specifies the position_between operator that is supported by the indextype and the position_im type that implements the index interface. Refer to "Using Extensible Indexing" for an extensible indexing scenario that uses this indextype:

CREATE INDEXTYPE position_indextype
   FOR position_between(NUMBER, NUMBER, NUMBER)
   USING position_im;