What Compiling Does
What happens when a class is compiled? The Studio Output window gives us some clues.
![generated description: newcompileroutput 20111](images/tweb_newcompileroutput_20111.png)
First, the class definition is processed. If it contains any errors, they are reported during this phase.
Second, the system automatically creates a table definition in the database, making our Film data immediately available via SQL.
Third, the system creates a routine, which is the compiled form of a class definition and one of the “secrets” behind the superb performance delivered by Caché applications.