Chapter 1

1. SAS manages data using the procedural data step language, so the programmer must spell out exactly how queries will execute. SQL is a declarative language, so the programmer declares the query results they want, and an optimizer program determines how the query will execute.

2. Setting criteria using the WHERE clause will cause SAS to skip over reading records that do not meet the criteria. If the criteria are set on an IF rather than a WHERE clause, SAS will read the whole record first and evaluate the criteria afterward.

3. SAS/ACCESS.

4. It is a high-cardinality variable that is used repeatedly in WHERE clauses in processing.

5. It is best to store data independently of SAS code for privacy reasons, and it is usually easier to enter the data into a spreadsheet and then read it into SAS. However, it is possible to use SAS to enter data, and then save the resulting dataset as the live data.

6. By using all SAS components, you can achieve the fastest I/O possible...