The main purpose of is to allow you to track and chart the results of any custom SQL over a period of time.  You define a SQL statement to be fired by SqlTac at a defined interval.   The result set of your SQL statement can contain any number of columns, but only one row.  This one row is called an observation.  Every time SqlTac fires your SQL statement the new observation will be appended to a collection.  You decide whether the collection is stored in a XML file or in a Database table.

SqlTac allows you to define a custom chart for each tracked item.  Charts are based on the observations contained in the collection.  SqlTac supports over 32 different chart types.   You can add more than one series to any single chart.   Your chart definitions are stored along with your custom SQL, so the next time you start SqlTac all of your preferences are restored.

SqlTac wll only takes observations while SqlTac is running.  If you run multiple instances of SqlTac at a time, only one instance will actually perform the tracking, all other instances will only listen.