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The correct OPTION is (a) Multisets

Best explanation: The COLLECTIONS on which aggregate functions can operate are called as multisets. Sets are a special CASE of multisets.

The correct choice is (a) True

To ELABORATE: The DIVISION is a binary OPERATION that is labeled as R ÷ S. The result CONSISTS of the restrictions of tuples in R to the attributes unique to R, i.e., in the relation R but not in the relation S.

Right ANSWER is (a) Assignment

Explanation: UPDATING, DELETING and Inserting in relational ALGEBRA is done using the assignment operator.

The correct OPTION is (b) ⟖

Best explanation: The SYMBOL of the right OUTER JOIN is similar to the symbol of the natural join but it has two dashes on the top and bottom right side.

The correct OPTION is (a) ⟕

To ELABORATE: The symbol of the left outer JOIN is similar to the symbol of the NATURAL join but it has two dashes on the top and bottom left side.

Correct choice is (C) select

To ELABORATE: The project operation’s function in relational algebra is identical to the select CLAUSE in SQL STANDARD. It is used to LIST the attributes that are to be displayed.

Right choice is (c) Manipulate

Explanation: There does not exist any OPERATION named as manipulate operation in RELATIONAL algebra. The union gives the union of two sets. Project is SIMILAR to SELECT in SQL and select is similar to where in SQL.

The correct choice is (B) False

To elaborate: In OLAP, ANALYSTS cannot view a dimension in DIFFERENT levels of detail. The different levels of detail are classified into a hierarchy.

Correct answer is (d) DRILL down

To explain: OLAP systems permit USERS to VIEW the data at any LEVEL of granularity. The process of moving from finer granular data to coarser granular data is called as drill-down.

The correct choice is (a) True

Explanation: OLAP SYSTEMS can be IMPLEMENTED as client-server systems. In fact most of the current OLAP systems are implemented as client-server systems.

Correct choice is (d) None of the mentioned

Easiest explanation: HOLAP means HYBRID OLAP, MOLAP means MULTIDIMENSIONAL OLAP, ROLAP means relational OLAP. This means all of the above OLAP SYSTEMS exist.

The correct choice is (c) Decode

For EXPLANATION: The decode function allows substitution of values in an ATTRIBUTE of a tuple. The decode function does not always work as we MIGHT like for null values because predicates on null values EVALUATE to UNKNOWN.

The correct option is (B) 2

The best explanation: Cross-tabs enable analysts to view two dimensions of multi-dimensional DATA, ALONG with the summaries of the data.

The CORRECT choice is (C) Roll up

The explanation is: OLAP systems PERMIT users to view the data at any LEVEL of granularity. The PROCESS of moving from finer granular data to coarser granular data is called as roll-up.

Correct ANSWER is (B) Multi-dimensional data

Explanation: Data that can be MODELLED as dimension ATTRIBUTES and measure attributes are called multi-dimensional data.

Right CHOICE is (d) ONLINE Analytical Processing

To EXPLAIN: The full FORM of OLAP is Online Analytical Processing. It is an interactive system that gives various features to analysts.

Right CHOICE is (a) java.sql

For explanation: The java.sql PACKAGE comprises of the core JDBC API. JDBC is an APPLICATION program INTERFACE which contains all the functions to link and execute database functions in Java.

The correct CHOICE is (d) 4

To EXPLAIN: There are four types of JDBC drivers which are named JDBC TYPE 1,2,3,4 drivers respectively.

Right CHOICE is (a) True

Easiest explanation: Recursive QUERIES can be used in SQL in ORDER to verify a condition repeatedly. SQL ALLOWS recursive queries.

The CORRECT option is (a) Trigger

Best EXPLANATION: A trigger is a STATEMENT that the SYSTEM executes whenever a database is modified. Immediately after the specified modification of the database is complete, the trigger statement GETS executed and then the execution is continued.

Right answer is (b) PERSISTENT storage module

To explain I would SAY: The part of SQL that DEALS with the SQL SUPPORTS constructs is called as Persistent Storage Module (PSM). The SQL supports construct give it almost all the power of a general purpose programming language.

Right choice is (b) False

To EXPLAIN I would SAY: Developers can WRITE their own functions into SQL by using the create function STATEMENT.

The correct choice is (a) JAVA DATABASE Connectivity

Explanation: The FULL form of JDBC is Java Database Connectivity. This full form is no longer widely used and the abbreviation is MOSTLY used everywhere.

The CORRECT option is (d) All of the mentioned

Easy explanation: Dynamic SQL ALLOWS the PROGRAM to construct the queries in character STRING format, it submits them, and then retrieves the data into the program variables one tuple at a time.

Right choice is (d) All of the mentioned

Easy explanation: The SQL standard includes the privileges select, insert, UPDATE and delete. This privilege set can be granted or revoked among the USERS.

Correct ANSWER is (a) True

Easiest EXPLANATION: SQL allows the CREATION of new data types using the “create typeasfinal;” statement.

Correct CHOICE is (d) lint

Explanation: clob and blob are CALLED large object data types. They can be used to store values that can GO to the size of GIGABYTES. Number is used to store the BASIC integer data type.

The correct answer is (a) True

Easiest EXPLANATION: Most of the widely used database management systems including oracle CURRENTLY do not support complex CHECK CONDITIONS.

Right answer is (a) Assertion

For EXPLANATION I WOULD SAY: An assertion is a predicate that we expect the DATABASE to always SATISFY. Domain constraints and referential integrity constraints are special forms of assertions.

Correct choice is (b) Subset dependencies

The BEST explanation: Referential integrity constraints are also called as subset dependencies. It is called so because the set of foreign KEY values in R1 of R2 must be a subset of the set of primary key values in r2.

Right choice is (C) It is used to preserve referential integrity in a RELATION

The EXPLANATION is: It is used to preserve referential integrity in the relation. When an attribute of a relation is the foreign key in another relation, deleting it causes referential integrity problems. The on delete CASCADE solves this problem by forcing us to delete the foreign key FIRST.

The CORRECT option is (a) It ENSURES that no two values under an attribute are identical

Explanation: The purpose of the UNIQUE clause is to ensure that no two values under the same attribute are identical. PRIMARY KEYS are unique by default.

The correct answer is (b) It ensures that DATA is entered into the database

To explain: The not NULL constraint ensures that data is entered into the database. It DISPLAYS an error message whenever a data FIELD mentioned is left empty.

Correct choice is (c) identical

The best I can explain: Identical is not an ALLOWED integrity CONSTRAINT in SQL. Not null prevents null VALUES and unique only allows unique values to be entered. Check CHECKS for a given condition.

Correct choice is (b) ROLLBACK work

For EXPLANATION I WOULD say: The Rollback work statement causes the statements to undo all the updates performed on the transaction. The DATABASE is then restored to the state of what it was before the first statement of the transaction was executed.

The CORRECT choice is (B) False

Explanation: We can update a VIEW only if it has a single database relation in the “from” clause.

Correct option is (d) MATERIALIZED views

The EXPLANATION is: If the actual RELATIONS used in the view DEFINITION change, the view is updated immediately. Such views are CALLED Materialized views. Materialized views help to keep the database up-to-date.

Right choice is (a) True

For explanation I would say: ONE view can be used to define another view in its EXPRESSION. This further improves the writability of the code as we are reducing the ENTIRE logical model.

Right choice is (d) It is syntactically wrong and does not give a result

Best EXPLANATION: immediately after specifying the NAME of the VIEW, we have to WRITE the “as” keyword. So this query does not give any result as it is syntactically incorrect.

The correct option is (c) CREATE VIEW

To explain: We use the create view command to DEFINE a view in SQL.

Correct option is (b) A relation that is not a PART of the schema but is a virtual relation

Explanation: A relation that is not a part of the schema but is a virtual relation is called as VIEW. Views improve writability as viewing the entire LOGICAL MODEL is not feasible.