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. IBM Text Search for Db2 for z/OS provides text search capability for text columns that are stored in a Db2 table. This text search server offers excellent query performance and scalability by integrating optimization and state-of-the-art search technologies.

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®, Linux on IBM Z®, 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.

IBM Text Search for Db2 for z/OS supports multiple collections. A collection contains one text search index and the index specific options for parsing, indexing, and searching.

IBM Text Search for Db2 for z/OS does not have a graphical user interface. However, the text search server provides command-line tools that you can use for common tasks, such as configuring and administering the text search server, creating a synonym dictionary for a collection, and diagnosing problems.

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.