To create an etx index, you specify the etx access
method in the USING clause of the CREATE INDEX statement.
For example, suppose your search text is contained in the column description,
of type CLOB, in the videos table. To create an etx index
named desc_idx for this table that is stored in the sbspace sbsp1,
use the following syntax:
CREATE INDEX desc_idx ON videos (description etx_clob_ops)
USING etx in sbsp1;
The operator class etx_clob_ops is specified directly after description,
the column to be indexed. Be sure to specify the correct operator
class for the type of the indexed column. See the table in the previous
section for valid operator class names and their corresponding data
types.
An sbspace is a logical storage area that contains one or more
chunks that store BLOB and CLOB data types. See the HCL OneDB™
Administrator's Guide for
your database server for detailed information about sbspaces and smart
large objects.
Important: The following options to the
CREATE INDEX statement cannot be specified when you create etx indexes:
CLUSTER, UNIQUE, DISTINCT, ASC, DESC, and FILLFACTOR.
The following figure shows how the DataBlade® module
creates an etx index that uses the Excalibur Text Retrieval
Library (TRL). Figure 1: The
etx index creation
The etx access method supports both table and index fragmentation.
