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.