Aliases
An alias is an alternative name for an object such as a module,
table or another alias. It can be used to reference an object wherever that object can be referenced
directly.
Soft invalidation of database objects
When soft invalidation is active, an object
can be dropped even if other running transactions are using it. Transactions
that were using the dropped object are permitted to continue, but
any new transaction will be denied access to the dropped object.
Automatic revalidation of database objects Automatic revalidation is a mechanism whereby
invalid database objects are automatically revalidated when accessed
at run time.
Creating and maintaining database objects
When creating some types of database objects,
you should be aware of the CREATE with errors support, as well as
the REPLACE option.