There are several ways to improve query performance, including the following:
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using indexes and composite indexes
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using the keyword ALL in set operations when you know that there are no
duplicate rows, or when it does not matter if you have duplicate rows in the
result table
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omitting the ORDER BY clause when you create tables and views
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using in-line views instead of temporary tables (or vice versa)
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using joins instead of subqueries
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using WHERE expressions to limit the size of result tables that are created
with joins
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using either PROC SQL options, SAS system options, or both to replace a PUT
function in a query with a logically equivalent expression
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replacing references to the DATE, TIME, DATETIME, and TODAY functions in a
query with their equivalent constant values before the query executes
- disabling the remerging of data when summary functions are used in a query
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