Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...

The indexes on a the tables of a large database make a huge difference in its performance and utility. Without an index, locating a single record in a large table can take several seconds; with the ...

This example uses DICTIONARY tables to show a list of the SAS files in a SAS data library. If you do not know the names of the columns in the DICTIONARY table that you are querying, use a DESCRIBE ...