IBM Text Search for DB2 for z/OS

The IBM® Text Search for DB2® for z/OS® enables a DB2 for z/OS user to issue SQL statements to satisfy familiar text search queries on data that is stored in a DB2 database.

The text search feature for DB2 for z/OS is powered by a text search server. You can use either IBM Text Search for DB2 for z/OS or IBM OmniFind Text Search Server for DB2 for z/OS to provide text search capability for text columns that are stored in a DB2 table. These text search servers offer excellent query performance and scalability by integrating optimization and state-of-the-art search technologies.

Note: Start of change IBM Text Search for DB2 for z/OS provides a newer version of the text search server than IBM OmniFind Text Search Server for DB2 for z/OS. To take advantage of the improved functionality, install or migrate to IBM Text Search for DB2 for z/OS. Unless explicitly stated otherwise, IBM Text Search for DB2 for z/OS and IBM OmniFind Text Search Server for DB2 for z/OS provide the same functionality.End of change

To use the text search feature, you enable support on a DB2 for z/OS subsystem. By enabling text search support, you can use the CONTAINS function and the SCORE function, which are built into the DB2 engine, to search text search indexes based on the search argument criteria that you specify.

You install a text search server on a supported Linux, zLinux, or Windows server. DB2 for z/OS uses a TCP/IP connection to communicate with the text search server.

Figure 1. The communication method between the DB2 subsystem and the text search server
Begin figure description. A user application sends an SQL statement to a DB2 subsystem. DB2 uses a TCP/IP connection to communicate with the text search server. End figure description.

A set of administration stored procedures is provided by DB2 for z/OS to start and stop text search support and to create, update, drop, restore, and take over text search indexes. For example, in the case of a planned outage of a text search server, you can use the stored procedure for restoring a text search index to copy that text search index to another text search server, where you can use the text search index during the outage. These stored procedures are provided with DB2 for z/OS and are defined during installation.

Although the text search index is maintained by a text search server on its local disk, the master copy of the text search index is stored in the DB2 tables. You can access the text search index from all DB2 subsystems in a data sharing group. All text search servers that are configured for a particular DB2 subsystem or data sharing group can access the master copy of the text search index.