Querying database monitor view 3020 - Index advised

 

The index advisor information can be found in the Database Monitor view 3020 - Index advised (SQE).

The advisor information is stored in columns QQIDXA, QQIDXK and QQIDXD. When the QQIDXA column contains a value of 'Y' the optimizer is advising you to create an index using the key columns shown in column QQIDXD. The intention of creating this index is to improve the performance of the query.

In the list of key columns contained in column QQIDXD the optimizer has listed what it considers the suggested primary and secondary key columns. Primary key columns are columns that should significantly reduce the number of keys selected based on the corresponding query selection. Secondary key columns are columns that may or may not significantly reduce the number of keys selected.

Column QQIDXK contains the number of suggested primary key columns that are listed in column QQIDXD. These are the left-most suggested key columns. The remaining key columns are considered secondary key columns and are listed in order of expected selectivity based on the query. For example, assuming QQIDXK contains the value of 4 and QQIDXD specifies 7 key columns, then the first 4 key columns specified in QQIDXK is the primary key columns. The remaining 3 key columns are the suggested secondary key columns.

 

Parent topic:

Query optimizer index advisor