For what purpose is PROC SQL used in SAS?

PROC SQL is a powerful procedure within SAS that allows users to perform SQL queries, which are essential for data manipulation. Specifically, it enables users to select, filter, join, and aggregate data from one or more tables in a manner similar to traditional SQL databases. This capability allows for complex querying and data operations to be executed succinctly within the SAS environment, streamlining the data analysis process.

For example, using PROC SQL, you can easily retrieve specific columns from a dataset, apply conditions to restrict data retrieval, join tables to combine datasets based on related fields, and create new datasets directly from query results. The flexibility and familiarity of SQL syntax make data manipulation tasks more intuitive for users who are accustomed to working with relational databases.

The other options do not reflect the primary purpose of PROC SQL. Creating graphical displays pertains to procedures that specifically handle visualizations, defining formats relates to data representation more generally, while merging datasets is typically accomplished using other procedures like DATA steps or PROC DATASETS in SAS. Therefore, option B accurately captures the core functionality of PROC SQL in facilitating data manipulation through SQL queries.