DataBlade Module Development Overview Informix DataBlade Modules

The Excalibur Text Search DataBlade module enables you to search your data in ways that are faster and more sophisticated than the keyword matching that SQL provides. Excalibur text search capabilities include phrase matching, exact and fuzzy searches, compensation for misspelling, and synonym matching. The Excalibur Text Search DataBlade module can search any type of text.

The Excalibur Text Search DataBlade module uses dynamic links in the Excalibur class library, or text search engine, to perform the text search section of the SELECT statement instead of having the database server perform a traditional search. The text search engine is specifically designed to perform sophisticated and fast text searches. It runs in one of the database server-controlled virtual processes.

The Excalibur Text Search DataBlade module provides four kinds of objects to extend your Informix database server: the etx access method, the filter utility, the etx_contains() operator, and text search routines.

The etx access method allows you 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.

To take advantage of the etx access method, you must store the data you want to search-called search text-in a column of type IfxDocDesc, BLOB, CLOB, CHAR, VARCHAR, or LVARCHAR. The first data type in this list, IfxDocDesc, is a data type that Informix designed specifically for use with text access methods. The most popular data types for large documents are BLOB and CLOB.

When you store your documents in a column, you do not need to manually convert them from their proprietary format into ASCII when creating an etx index; the Excalibur Text Search DataBlade module does this for you. One of the components of the Excalibur Text Search DataBlade module is a filtering utility that recognizes a number of document formats and converts them into ASCII form whenever needed.

You use the etx_contains() operator within SELECT statements to perform searches of etx indexes.

In addition to the etx_contains() operator, the Excalibur Text Search DataBlade module supplies several routines that you can use to perform tasks such as creating and dropping synonym and stopword lists.

For more information, see the Excalibur Text Search DataBlade Module User's Guide.