This illustration shows the stages in processing a SQL statement:

The database first opens, then parses the SQL statement. The database then decides whether or not to perform a query. If Yes, the database decides whether or not to do a DESCRIBE. If Yes, the database will do a DESCRIBE, then decides whether or not to describe more. If the database does not describe (or describe more), it will DEFINE. The database may Define more, or it may not, in which case it decides whether or not to do a bind.

If the database performs a bind, it will decide whether to bind more. If it does not, it will EXECUTE, then PARALLELIZE the statement, after which it decides whether or not to performs a query. If Yes, the database performs a FETCH, after which it can fetch more. If No, it decides whether to execute others. If No, it closes. If Yes, it decides whether to reparse. If Yes, the process starts over again. If No, the process starts again from the "BIND" point.