Leveraging SAS® Viya® to Improve SAS® Processes

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This article was co-authored by Brian Kinnebrew and Steven Sober.

Did you miss the Ask the Expert session Best Practices in Migrating SAS Code to Leverage CAS? Not to worry, you can catch it on-demand at your leisure. A pdf of the presentation slides is attached.

The SAS Platform is greatly enhanced by SAS Viya. In this session, Steven Sober and Brian Kinnebrew share their experiences in leveraging SAS Viya to improve SAS processes. They explore technical insights and implementation details to CAS-enable your code, thus achieving faster results. These techniques are illustrated by real-life case studies.

In this session, you’ll learn the answers to questions such as:

• If a process cannot run in CAS, where does it run?
• What coding components are most frequently encountered in code reviews with customers?

Figure 1 Agenda of the Webinar Best Practices for Migrating SAS Code to leverage CAS

Here are some highlighted questions from the Q&A segment held at the end of the session for ease of reference.

1. What does CAS stand for?
   CAS stands for SAS Cloud Analytic Services. It's the In-memory processing engine in SAS Viya.
   
   
2. In general, if the base procedure is threaded in Base SAS, will it thread in CAS? Like Proc Sort, for example?

Yes, CAS is multi-threaded by default.

3. How can you tell if SPRE or CAS is running?

In the SAS log, there is a note that tells you if the procedure or DATA Step ran in CAS. If you write CASL code, that code will only run in CAS.

4. Is there a PROPCASE function in CAS?

This function is not supported in a DATA Step that runs in CAS.
https://go.documentation.sas.com/?cdcId=pgmsascdc&cdcVersion=9.4_3.4&docsetId=lefunctionsref&docsetT... 

5. Does a LIBNAME statement run in SPRE, and a CASLIB will run in CAS?

All data sources that are access by a LIBNAME will be processed in SPRE. All data sources that are accessed via a CASLIB will run in CAS provided.

a. The step is a CAS enabled procedure or all statements in the DATA Step are CAS enabled.

b. All source and target tables to the step reside in CAS.

Recommended Resources

• Course: Free SAS Viya Enablement
• Course: SAS Viya Learning Path

Reading material:

• Parallel Programming with the DATA Step: Next Steps (2018) required reading
• How to achieve repeatable results with distributed DATA Step BY Groups (2018) required reading
• Six reasons you should stop using the RANUNI function to generate random numbers (2013) required reading
• The following Base SAS procedures are CAS Enabled (2018)
• SAS^®SAS Viya^™3: FedSQL Programming for SAS^® Cloud Analytic Services (2018)
• FedSQL Implicit Pass-Through Facility in CAS (2018)
• What’s New in SAS® Data Connectors for SAS® SAS Viya® (2018)
• How to Emulate DESCENDING BY Variables in DATA Step Code that Runs Distributed in SAS® SAS Viya™ (2018)
• DATA Step in SAS® SAS Viya™: Essential New Features (2017)
• How to Emulate PROC APPEND in CAS (2017)
• Getting your SAS 9 code to run multi-threaded in SAS Viya 3.3 (2017)

Trial: Get an early preview of SAS® Visual Analytics on SAS® Viya™

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