Which of the following is generally used for performing tasks like creating the structure of the relations, deleting relation ?

Question

Accepted Answer

The correct option is (4):
Data Definition Language (DDL) is the precise set of SQL commands specifically designed to define and manage the structural components of a database. The term 'relation' in database theory is synonymous with 'table', and DDL commands are used to create, modify, and delete the structure of these tables. For instance, the CREATE command establishes the table structure (including columns and data types), the ALTER command modifies an existing structure (e.g., adding a column), and the DROP command is used for completely deleting a relation (table structure) from the database. DDL commands act on the database schema itself, setting the blueprint for where the data will be stored.

The incorrect option is (1):
DML (Data Manipulation Language) is fundamentally different as it deals with the data residing within the structural framework created by DDL. Its commands, such as INSERT, UPDATE, and DELETE, are used to add, modify, or remove the individual records (rows) in a table, not the table's definition or structure. While the DELETE command removes all rows, the DDL command DROP is required to remove the relation structure entirely. Therefore, DML's focus is on manipulating the content, not the container.

The incorrect option is (2):
The term "Query" generally refers to a request for information, most commonly executed through the SELECT statement (often considered part of DML or a separate Data Query Language - DQL). A query is primarily used for data retrieval or access. It is an action performed on the database's data. It does not represent the specialized language subset of SQL whose dedicated purpose is to define or delete the core tables and indices.

The incorrect option is (3):
A Relational Schema is the result or the output of the DDL process. It is the logical and physical description of the database structure—the collection of tables, their columns, and the relationships between them. It is the blueprint itself. Therefore, the schema is the object being created and deleted, not the language or tool used by the database administrator to perform those structural modifications.