“
When you execute a program that retrieves a small subset of rows from a large table, it can be time-consuming for PROC SQL to read the rows sequentially. In some situations, using an index on a table allows PROC SQL to access a subset of rows more efficiently. An index stores unique values for a specified column or columns in ascending value order, and includes information about the location of those values in the table. That is, an index is composed of value/identifier pairs that enable you to access a row directly, by value. For example, suppose you have created an index on your table that is based
”
”