Databases

Detecting de indexes, tables and packages not used on DB2

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:

Search more accessed tables in DB2

 It’s relatively simple and unfamiliar tool for the novices: db2top.

Using the option “T” (tables) and sorting the list (key “z”) using column 1.

The first position will be for the most accessed table.

If there is much difference between that and the rest during an appreciable period of normal use of the database, these tables would be candidates to improve their access or optimice their access to improve the overall performance,