Dropping typed tables

Dropping a typed table is similar to dropping a non-typed table. An important difference is that you must ensure that the table you are dropping has no subtables.

About this task

If the table you are trying to drop does have subtables, an error occurs. The following example shows how to drop the Architect table:

   DROP TABLE Architect;

When a subtable is dropped from a table hierarchy, the columns associated with the subtable are no longer accessible. Through substitutability, dropping a subtable has the semantic effect of deleting all the rows of the subtable from the supertables. This action can result in the activation of triggers or referential integrity constraints defined on the supertables.

Other database objects such as tables and indexes are not affected by the deletion, although packages and cached dynamic statements are marked not valid.

You can also drop an entire table hierarchy. Simply add the HIERARCHY clause to the DROP TABLE statement and name the root table of the hierarchy. For example:

   DROP TABLE HIERARCHY Person;

Dropping a table hierarchy does not result in the activation of triggers or referential integrity constraints.