Oracle Performance Optimization Operation 16: Using partitioned indexes

When you parse a partitioned index with the parse command, the range information for the data values for each partition is placed in the Oracle data dictionary.

Oracle can use this information to extract data partitions that are only related to SQL queries.

For example, suppose you have defined a partitioned index, and an SQL statement needs an index scan in an index partition.

Oracle accesses this index partition only, and a fast full scan of this index range is raised on this partition.

Because you do not need to access the entire index, you increase the speed of the query.

Oracle Performance Optimization Operation 16: Using partitioned indexes