Indexes (PDM)

An index is a data structure associated with a table that is logically ordered by the values of a key. It improves database performance and access speed.

You normally create indexes for columns that you access regularly, and where response time is important. Indexes are most effective when they are used on columns that contain mostly unique values.

• Creating an Index
  You can create the several types of index.
• Index Properties
  To view or edit an index'sproperties, double-click its Browser or list entry. The property sheet tabs and fields listed here are those available by default, before any customization of the interface by you or an administrator.
• Rebuilding Indexes
  Rebuilding indexes in a physical diagram automatically updates any changes that you have made to primary keys, foreign keys, or alternate keys in your model.
• Indexes in Query Tables
  You can create an index associated with the columns of a query table, which is a special type of view available in Oracle and DB2. These indexes are called view indexes. Query table indexes behave like indexes defined on tables, they are data structures that improve database performance and access speed. You normally create indexes for columns that you access regularly, and where response time is important.