Indexes are special reference tables that the SAS engine can use to speed up data retrieval. Simply put, an index is a pointer to data in a table. In this tips and tricks we will discuss how you can create and use SAS indexes.

Queries created couple of years ago could be more slow today just because the size of the tables queried increased, those tables could require an index?
Before jumping in the detail of the SAS Indexes, an overview of it's way of working will be described:

• Where are stored the indexes and what do they contains?
• Once created, are they used by default?
• What are the different kind of indexes?

• Create simple index
• Create composite index
• Create unique index

Finally, we will see different options allowing you to see if the indexes are used and to force to use them.

Prerequisites

You have some SAS experience and would like to create and use indexes in order to speed up your queries on big data.