DB2, from version 9.7, allows to know easily what indexes are not being used in a Database. The query is also for tables and packages.
This is a useful tool for tuning indexes and detecting problems in their use.
After version 9.7 DB2 includes a new LASTUSED field in the SYSCAT.INDEXES, SYSCAT.TABLES and SYSCAT.PACKAGES tables.
This field indicates the date of last use of indexes, tables or packages.
For example, to query unused indexes since 1/1/2019, you could use this simple query:
SELECT INDSCHEMA, INDNAME, TABNAME FROM SYSCAT.INDEXES WHERE LASTUSED = '01/01/2019';
Very useful to drop nonsense indexes.