Implicit DDL

User-generated DDL operations can generate implicit DDL operations. For example, the following statement generates two distinct DDL operations.

CREATE TABLE customers (custID number, name varchar2(50), address varchar2(75), address2 varchar2(75), city varchar2(50), state (varchar2(2), zip number, contact varchar2(50), areacode number(3), phone number(7), primary key (custID));

The first (explicit) DDL operation is the CREATE TABLE statement itself.

The second DDL operation is an implicit CREATE UNIQUE INDEX statement that creates the index for the primary key. This operation is generated by the database engine, not a user application.