157 DBMS_XMLINDEX

The DBMS_XMLINDEX package provides an interface to implement asychronous indexing .

Using DBMS_XMLINDEX

Overview

Overview

Asynchronous Index Maintenance

The basic XMLIndex is maintained on every DML operation. However, given the computing costs, in many cases the availability of stale result is adequate. In such situations, it is desirable to defer index updates to a convenient time, for example to a time when the load on the database is low. Thus a mechanism for asynchronous index maintenance is provided.

Summary of DBMS_XMLINDEX Subprograms

This table list the package subprograms in alphabetical order.

Table 157-1 DBMS_XMLINDEX Package Subprograms

Subprogram	Description
CREATEDATEINDEX Procedure	Creates a secondary index for date values in the `VALUE` column of a `PATH` `TABLE` which is the storage table of an `XMLIndex`
CREATENUMBERINDEX Procedure	Creates a secondary index for number values in the `VALUE` column of a `PATH` `TABLE` which is the storage table of an `XMLIndex`
SYNCINDEX Procedure	Synchronizes the index manually

CREATEDATEINDEX Procedure

This procedure creates a secondary index for date values in the VALUE column of a PATH TABLE which is the storage table of an XMLIndex. The second form of the procedure allows for the date_index_clause to be set to an empty string.

Syntax

DBMS_XMLINDEX.CREATEDATEINDEX  (
   xml_index_schema   IN   VARCHAR2,
   xml_index_name     IN   VARCHAR2,
   date_index_name    IN   VARCHAR2,
   xmltypename        IN   VARCHAR2,
   date_index_clause  IN   VARCHAR2);

DBMS_XMLINDEX.CREATEDATEINDEX  (
   xml_index_schema   IN   VARCHAR2
   xml_index_name     IN   VARCHAR2,
   date_index_name    IN   VARCHAR2,
   xmltypename        IN   VARCHAR2);

Parameters

Table 157-2 CREATEDATEINDEX Procedure Parameters

Parameter	Description
`xml_index_schema`	Name of the owner of the `XMLIndex`
`xml_index_name`	Name of the `XMLIndex`
`date_index_name`	Name of the secondary index to be created for date values in the `VALUE` column of the `PATH` `TABLE` of `XMLIndex` named `xml_index_name` and owned by `xml_index_schema`
`xmltypename`	The type to which values in the `VALUE` column of the path table are to be cast. Acceptable values are the following strings: `DATETIME`, `TIME`, `DATE`, `GDAY`, `GMONTH`, `GYEAR`, `GYEARMONTH`, `GMONTHDAY`.
`date_index_clause`	Storage clause to be applied to the date index during its creation. This is a string argument appended to the `CREATE` `INDEX` statement for creating the date index

CREATENUMBERINDEX Procedure

This procedure creates a secondary index for number values in the VALUE column of a PATH TABLE which is the storage table of an XMLIndex.

Syntax

DBMS_XMLINDEX.CREATENUMBERINDEX (
   xml_index_schema   IN   VARCHAR2,
   xml_index_name     IN   VARCHAR2,
   num_index_name     IN   VARCHAR2,
   num_index_clause   IN   VARCHAR2,
   xmltypename        IN   VARCHAR2);

Parameters

Table 157-3 CREATENUMBERINDEX Procedure Parameters

Parameter	Description
`xml_index_schema`	Name of the owner of the `XMLIndex`
`xml_index_name`	Name of the `XMLIndex`
`num_index_name`	Name of the secondary index to be created for number values in the `VALUE` column of the `PATH` `TABLE` of `XMLIndex` named `xml_index_name` and owned by `xml_index_schema`
`num_index_clause`	Storage clause to be applied to the number index during its creation. This is a string argument appended to the `CREATE` `INDEX` statement for creating the number index.
`xmltypename`	The type to which values in the `VALUE` column of the path table are to be cast. Acceptable values are the following strings: `FLOAT`, `DOUBLE`, `DECIMAL`, `INTEGER`, `NONPOSITIVEINTEGER`, `NEGATIVEINTEGER`, `LONG`, `INT`, `SHORT`, `BYTE`, `NONNEGATIVEINTEGER`, `UNSIGNEDLONG`, `UNSIGNEDINT`, `UNSIGNEDSHORT`, `UNSIGNEDBYTE`, `POSITIVEINTEGER`.

SYNCINDEX Procedure

This function synchronizes an asynchronously maintained XMLIndex. It applies to the XMLIndex changes that are logged in the pending table, and brings the path table up-to-date with the base XMLTYPE column.

Syntax

DBMS_XMLINDEX.SYNCINDEX (
   xml_index_schema      IN VARCHAR2,
   xml_index_name        IN VARCHAR2);

Parameters

Table 157-4 SYNCINDEX Procedure Parameters

Parameter	Description
`xml_index_schema`	Name of the owner of the XMLIndex
`xml_schema_name`	Name of the XMLIndex

Examples

EXEC DBMS_XMLINDEX.SYNCINDEX('USER1', 'SS_TAB_XMLI');