Remember that sql_trace (possibly started by a logon trigger that calls the packaged procedure dbms_support.start_trace) is your best friend when you are testing. Many of the enhancements and features that appeared in Oracle9 i Database were supported by PL/SQL packages and recursive SQL. Expect more of the same approach to appear in Oracle Database 10g.
If you switch on sql_trace when testing a feature, you may find out what Oracle Database 10g is doing under the covers to support that feature, and discover that a feature that looks good on paper has a nasty side effect that makes it unsuitable for your production system.
Another little trick for discovering hidden costs when you start to test new data structures is to start with a clean schema, create an example of the new data structure, and then query the USER_OBJECTS view to discover what hidden objects Oracle has created to support that structure.
upgrade. The Oracle upgrade manual provides a complete set of instructions on how to perform this type of upgrade.
Finally, you can use the SQL*Plus copy command or the SQL create table as select command to move your database data to a new Oracle Database 10g instance. Again, the Oracle upgrade manual provides a complete set of instructions on how to perform this type of upgrade.
As an author who admits to hating GUIs, I rather like the Database Configuration Assistant (DBCA). Creation of a small database is a great way to test your new Oracle software install. Oracle Database 10g has added new functionality to the DBCA, including the ability to perform Real Application Cluster database installs and configuration of Automatic Storage Management (a new feature that is described later in this chapter).
In the previous section you might have noticed that when you upgrade your Oracle database to Oracle Database 10g, you need to create a new tablespace called SYSAUX. Also, when you create your first Oracle Database 10g database, Oracle will create SYSAUX as well. The SYSAUX tablespace is a new tablespace component in Oracle