Database Management System MCQs

The predicate in a where clause can involve Boolean operations such as and. The result of true and unknown is_______ false and unknown is _____ while unknown and unknown is _____

In an employee table to include the attributes whose value always have some value which of the following constraint must be used?

Using the ______ clause retains only one copy of such identical tuples.

The primary key must be

You attempt to query the database with this command: SELECT nvl (100 / quantity, NONE) FROM inventory;

The result of _____unknown is unknown.

Aggregate functions are functions that take a ___________ as input and return a single value.

All aggregate functions except _____ ignore null values in their input collection.

A Boolean data type that can take values true, false, and________

The ____ connective tests for set membership, where the set is a collection of values produced by a select clause. The ____ connective tests for the absence of set membership.

The phrase “greater than at least one” is represented in SQL by _____

We can test for the nonexistence of tuples in a subquery by using the _____ construct.

SQL applies predicates in the _______ clause after groups have been formed, so aggregate functions may be used.

Aggregate functions can be used in the select list or the_______clause of a select statement or subquery. They cannot be used in a ______ clause.

The ________ keyword is used to access attributes of preceding tables or subqueries in the from clause.

Which of the following creates a temporary relation for the query on which it is defined?

Subqueries cannot:

Which of the following is not an aggregate function?

The EXISTS keyword will be true if:

How can you find rows that do not match some specified condition?

Which of the following creates a virtual relation for storing the query?

Which of the following is the syntax for views where v is view name?

Materialised views make sure that

Updating the value of the view

SQL view is said to be updatable (that is, inserts, updates or deletes can be applied on the view) if which of the following conditions are satisfied by the query defining the view?

For the view Create view instructor_info as SELECT ID, name, building FROM instructor, department WHERE instructor.dept name= department.dept name;

A _________ consists of a sequence of query and/or update statements.

Which of the following makes the transaction permanent in the database?

In order to undo the work of transaction after last commit which one should be used?

Consider the following action: TRANSACTION..... Commit; ROLLBACK;

In case of any shut down during transaction before commit which of the following statement is done automatically?

In order to maintain the consistency during transactions, database provides

A transaction completes its execution is said to be

Which of the following is used to get back all the transactions back after rollback?

______ will undo all statements up to commit?

To include integrity constraint in an existing relation use :

Which of the following is not an integrity constraint?

Foreign key is the one in which the ________ of one relation is referenced in another relation.

Domain constraints, functional dependency and referential integrity are special forms of _________

Which of the following is the right syntax for the assertion?

Data integrity constraints are used to:

Which of the following can be addressed by enforcing a referential integrity constraint?

Dates must be specified in the format

A ________ on an attribute of a relation is a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.

Which of the following is used to store movie and image files?

The user defined data type can be created using

Values of one type can be converted to another domain using which of the following?

Which of the following closely resembles Create view?

In contemporary databases, the top level of the hierarchy consists of ______ each of which can contain _____

Which of the following statements creates a new table temp instructor that has the same schema as an instructor.