Missing Indexes

Indexes which are defined in the ABAP Dictionary but are missing in the database or indexes which were created in the database but are unknown to the ABAP Dictionary are an especially important factor in performance problems. For this reason, there is a separate Missing indexes display, even though one is already included in the full check accessed via Database <-> ABAP Dictionary consistency.

Incorrectly defined and superfluous indexes may also impair database performance. They can cause the database optimizer to make an inefficient index selection. Moreover, whenever the database is updated, the superfluous indexes also have to be taken into account.

1. Choose Tools → Administration → Computing Center → Management System → Control → Performance Menu → Database → Tables / Indexes → Missing indexes.

   Alternatively, use transaction code DB02.

2. Choose Missing indexes.

The tables in the ABAP Dictionary and the database tables are analyzed. The data displayed either comes from the regular batch runs for performance analysis, or it is created/updated with Refresh.

Missing indexes may occur if you ignore an error message when creating a table (table created, index not created) or if an index is deleted. The latter case may occur during an incorrect reorganization.

Indexes that are defined in the ABAP Dictionary but are missing in the database can be created in the database directly from the display (Creating Objects in the Database). You can also display the respective definition in the ABAP Dictionary (Displaying Object Definitions).

See also:

Consistency Checks

Database Tables without a Unique Index

Naming Conventions for Indexes