The correct answer is: D. All of the above
Data Definition Language (DDL) is a set of commands used to define the structure of a database. It is used to create, alter, and drop database objects such as tables, views, and constraints.
DDL commands are typically executed by a database administrator (DBA) or other authorized user. They are not directly executed by end users.
DDL commands are typically stored in a database schema. A schema is a collection of definitions for database objects.
The following are some examples of DDL commands:
CREATE TABLE– Creates a new table in the database.ALTER TABLE– Changes the structure of an existing table.DROP TABLE– Deletes an existing table from the database.CREATE VIEW– Creates a view of data from one or more tables.CREATE CONSTRAINT– Creates a constraint on a table.
DDL commands are an important part of database management. They allow users to create and manage the structure of their databases.
A. describes how data are structured in the data base
This is true. DDL commands are used to define the structure of a database. They specify the tables, views, and constraints that make up the database.
B. specifies for the DBMS what is required; the techniques used to process data
This is not true. DDL commands do not specify the techniques used to process data. This is done by the database management system (DBMS).
C. determine how data must be structured to produce the user’s view
This is true. DDL commands determine how data must be structured to produce the user’s view. The user’s view is the way that the user sees the data in the database.
E. None of the above
This is not true. All of the above are true statements about DDL commands.