Specifies the process to determine which observations meet the condition or conditions of a WHERE expression.
Valid in: | Configuration file, SAS invocation, OPTIONS statement, System Options window |
Category: | System administration: Performance |
Default: | COST |
Engine: | SPD Engine only |
specifies that the SPD Engine decides which evaluation strategy to use to optimize the WHERE expression. This process calculates the number of threads to be used, which minimizes the overhead of spawning underused threads. This is the default.
is a multi-threaded index evaluation strategy that can quickly determine the rows that satisfy the WHERE expression using multiple threads. The number of threads that are spawned to retrieve the observations is equal to the THREADNUM= value.
is a single-threaded index evaluation strategy that is used for a simple or compound WHERE expression. All the key variables have a simple index and no condition tests for non-equality. Multi-threading might be used to retrieve the observations.