Question

An application developer can guard against certain snapshot anomalies by appending a ______ clause to the SQL select query.

(a) For update

(b) For read

(c) For write

(d) None of the mentioned

The question was asked in an international level competition.

My doubt stems from Snapshot Isolation topic in section Concurrency Control of Database Management

Answer 1

The correct option is (a) For update

The explanation is: Adding the for update clause causes the system to treat data that are read as if they had been updated for purposes of concurrency control.