see System Quirks
The SQL/MP / Index screen presents information about files used to provide ordered access to data.
Indexes are comprised of data accessible in an ordered manner. As indexes physically grow in size, the number of levels within the index also increase, which can affect performance. Generally speaking, access to a data record requires the number of index levels plus 1. As such, it is advisable to maintain index levels as low as possible. Note that disk cache generally favors indexes over data so the number of physical drive I/Os is usually reduced by adding cache.
The screen columns ActIndx, IndexL and IndxVar, as shown below, provide the Actual Index levels at the time of screen display, the Index levels recorded in the associated Catalog and the difference. Sorting by and/or comparing these values provides two pieces of information: 1) how many index levels are physically present, and 2) SQL/MP compiles may not be choosing the most optimum access path if the catalog differs greatly from the physical underlying files.
