How can I check if an index is being used in DB2?

To check if indexes are used in a DB2 database, you can use the EXPLAIN command combined with the db2exfmt tool. Here is an example of the steps:

First, connect to the database in the DB2 command line or terminal.

Execute the following SQL statement to enable the execution plan tracing.

   SET CURRENT EXPLAIN MODE = YES;

3. Execute the query statement that you wish to check. For example:

   SELECT * FROM your_table WHERE column_name = 'value';

Execute the following SQL statement to retrieve execution plan information:

   EXPLAIN PLAN FOR <your_query>;

is the query statement that you executed previously.

Use the following SQL statement to display execution plan information:

   SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY());

This will return the execution plan information for the query, including whether indexes were used.

In the execution plan information, you can view the OPERATION column. If the operation is INDEX SCAN or INDEX SEEK, it means that an index was used. Additionally, you can also check the OBJECT_NAME column, which contains the name of the index being used.

Please note that in order to carry out the above steps, you must have sufficient permissions to execute these commands, and you need to install and configure the tools and environment of DB2.