Debugging data step code
As you must realize by now, well-formed data step code is critical to efficiency in SAS. Therefore, once we write data step code for an enduring process (such as ETL), it seems like we are always editing it to improve it. We may even rewrite it to add arrays or macro processing.
However, each time we write and rewrite data step code, we create the opportunity for bugs. For this reason, and because the data step code is so complicated to begin with, there is an extensive array of strategies for troubleshooting and debugging SAS data steps. Many are covered in the SAS white paper Errors, Warnings, and Notes (Oh My) A Practical Guide to Debugging SAS Programs by Lora D. Delwiche and Susan J. Slaughter (link available in the Further reading section).
Because this topic is so extensive, we cannot give it a full treatment here. Instead, we will just cover the basics of debugging data step code and refer to the white paper and other resources for further information...