GATE | GATE MOCK 2017 | Question 62

Which of the given options define a transaction correctly?
(A) A transaction consists of DDL statements on the database schema.
(B) A transaction consists of COMMIT or ROLLBACK in a database session.
(C) A transaction consists of either a collection of DML statements or a DDL or DCL or TCL statement to form a logical unit of work in a database session.
(D) A transaction consists of collection of DML and DDL statements in different sessions of the database.

Answer: (C)

Explanation:

A database transaction consists of one or more DML statements to constitute one consistent change in data, or a DDL statement or a DCL command (GRANT or REVOKE). It starts with the first DML statement and ends with a DCL or DDL or TCL (COMMIT or ROLLBACK) command. Note that DDL and DCL commands hold auto commit feature.


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