The ACCESS Procedure for PC Files

Performance and Efficient View Descriptors for PC Files

General Guidelines

When you create and use view descriptors, follow these guidelines to minimize the use of SAS resources and to reduce the time it takes to access data:
  • Select only the columns your SAS program needs. Selecting unnecessary columns adds extra processing time.
  • Where possible, specify selection criteria to subset the number of observations processed by SAS.
  • To present PC files data in sorted order, reference a view descriptor in a PROC SQL query. Otherwise, you might need to extract the data to sort it.

Extracting Data Using a View

It might be more efficient to use a view descriptor to extract PC files data and place it in a SAS data set.
  • A PC file is read every time a view Descriptor is referred to in a SAS program and is executed. It is better to extract data under these circumstances:
  • If the file is large and you use the data repeatedly in SAS programs.
  • If you use sorted data several times in a SAS program.
  • For added security, you can assign a password to the extracted SAS data set.