You can use indexes to improve the performance of data access. The various types of indexes have different features that you should consider when creating a particular type.

You typically determine which type of index you need to define after you define a table.

An index can have many different characteristics. Index characteristics fall into two broad categories: general characteristics that apply to indexes on all tables and specific characteristics that apply to indexes on partitioned tables only. The following table summarizes these categories.

Table 1. Index types for general, partitioned, and universal table spaces

Table or table space type	Index type
General (applies to all indexes)	Unique indexes Clustering indexes Padded indexes Not padded indexes Index on expression XML indexes Compressed indexes
Partitioned	Partitioning indexes Data-partitioned secondary indexes Non-partitioned secondary indexes Compressed indexes
Universal	Partitioning indexes (range-partitioned universal only) Data-partitioned secondary indexes (range-partitioned universal only) Non-partitioned secondary indexes Compressed indexes