- Avoid necessary DATA steps.
- IF statements before loading raw data.
- Use of WHERE statements in procedures.
- Drop unnecessary variables by using KEEP/DROP.
- Optimize size of variables using LENGTH.
- Use of IF-THEN-ELSE statements when possible instead of an IF-THEN sequence.
- Order of conditions inside the statements. The most frequent case should be the first.
- Multiple OR operators instead of IN.
- Use of DATA _NULL_ when creating Reports.
- Use of permanent data sets in libraries.
- use of PROC DATASETS to modify variables, instead of DATA statements.
- PROC APPEND to join similar datasets.
- Use RETAIN statement to initialize contents
- Avoid unnecessary sorts: two-level sort instead of one-level sort and a two-level sort.
- Sort only what we have to sort
- Sort: Using NOEQUALS if we do not neet the relative order.
Saturday, October 30, 2010
SAS - Efficiency
Some SAS recommendations for making the code more efficient.