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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for HCL OneDB™.
HCL OneDB™ extensions and DataBlade® modulesThese topics describe how to use built-in database extensions and separately installed DataBlade® modules.
Excalibur Text Search DataBlade® Module User's GuideThese topics describe the module and how to access and use its components.
OverviewThis section provides an overview of the module.
Components of the Excalibur Text Search DataBlade® moduleThe module has three principal components: the etx access method, the etx_contains() operator, and the supporting routines defined for the DataBlade® module.
The etx access methodUse the etx access method to call on the Excalibur Text Retrieval Library to create indexes that support sophisticated searches on table columns that contain text. The indexes that you create with the etx access method are called etx indexes.
Operator classesWhen you create an etx index, you must specify the operator class defined for the data type of the column being indexed. An operator class is a set of functions that HCL OneDB™ associates with the etx access method to optimize queries and build indexes.

Operator classes

When you create an etx index, you must specify the operator class defined for the data type of the column being indexed. An operator class is a set of functions that HCL OneDB™ associates with the etx access method to optimize queries and build indexes.

Each of the seven data types that supports an etx index has a corresponding operator class that must be specified when creating the index. The following table lists each data type and its corresponding operator class.

Table 1. Data types and their corresponding operator classes
Data type	Operator class
BLOB	etx_blob_ops
CLOB	etx_clob_ops
LVARCHAR	etx_lvarc_ops
CHAR	etx_char_ops
VARCHAR	etx_varc_ops
IfxDocDesc	etx_doc_ops
IfxMRData	etx_mrd_ops

Important: You must always specify an operator class when you create an etx index, even though each supported data type has only one operator class defined for it. Consult the preceding table to be sure that you specify the correct operator class for the data type of the column you want to index.

The following section shows an example of specifying an operator class when creating an etx index.