Optimizing System Performance

Techniques for Optimizing Memory Usage

If memory is a critical resource, several techniques can reduce your dependence on increased memory. However, most of them also increase I/O processing or CPU usage.

However, by increasing memory available to SAS by increasing the value of the MEMSIZE= system option (or by using the MEMLEAVE= option, in some operating environments), you can decrease processing time because the amount of time that is spent on paging, or reading pages of data into memory, is reduced. The SORTSIZE= and SUMSIZE= system options enable you to limit the amount of memory that is available to sorting and summarization procedures.

You can also make tradeoffs between memory and other resources, as discussed in Reducing CPU Time by Using More Memory or Reducing I/O. To use the I/O subsystem most effectively, you must use more and larger buffers. However, these buffers share space with the other memory demands of your SAS session.

Operating Environment Information: The MEMSIZE= system option is not available in some operating environments. If MEMSIZE= is available in your operating environment, it might not increase memory. See the documentation for your operating environment for more information. [cautionend]

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