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GK One-Line Question & Answer

15541+ short questions with short answers, covering every category and sub-category on the site — no long articles to scroll through. Good for a fast recap before an exam, or a few minutes of daily practice.

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DBMS → Indexes 3

Which type of entity represents a logical generalization whose actual occurrence is represented by a second, associated entity?
Archetype entity
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Which of the following is an aggregate function in SQL?
Max
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The concept of locking can be used to solve the problem of
Lost update
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DBMS → Transactions 3

Which of the following is the preferred way to recover a database after a transaction in progress terminates abnormally?
Rollback
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Which command is used to add a column to an existing table?
Alter
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A schedule S of n transactions is serializable if it is equivalent to some
Serial schedule of the same n transactions.
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DBMS → Concurrency Control 3

Concurrency control is important for which of the following reasons?
To ensure data integrity when updates occur to the database in a multiuser environment
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A deadlock exists in the system if and only if the wait for graph:
has a cycle in it
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In two-phase locking protocol.
All locking operations precede the first unlock operation.
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DBMS → Deadlock 3

The transaction log includes which of the following?
The essential data of the record
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Rollback of transactions is normally used to:
recover from transaction failure
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Transaction timestamp is:
Unique identifier assigned to each transaction.
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DBMS → Database Security 2

What is the type of Oracle backup in which all uncommitted changes have been removed from the datafiles?
Consistent backup
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The DBMS language component which can be embedded in a program is
The data manipulation language (DML).
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DBMS → PL/SQL 2

Which of the following is true concerning a procedure?
They include procedural and SQL statements.
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A DBMS query language is designed to
all of the above.
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DBMS → Introduction to DBMS 2

A CASE SQL statement is which of the following?
A way to establish an IF-THEN-ELSE in SQL.
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Which of the following is correct
None of these
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DBMS → Database Architecture 2

Which of the following statements is true concerning routines and triggers?
Both consist of procedural code.
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Which of the following is a valid SQL type?
All of the above
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DBMS → Data Models 2

How many bytes does each character in the UTF8 encoding take up?
All mentioned above
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Which of the following is a legal expression in SQL?
SELECT NAME FROM EMPLOYEE;
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DBMS → ER Model 2

PL/SQL has two types of subprograms, procedures and functions. Which subprogram isused to compute a value?
Function
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If every non-key attribute is functionally dependent on the primary key, then the relation will be in:
Third normal form
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DBMS → Relational Model 2

Which datatype is not allowed in the definition of PL/SQL record?
A Collection
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Given the functional dependencies X →W; X→Y; Y→Z and Z→PQ Which of the following doesn’t hold well?
W→Z
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DBMS → Normalization 2

In the SQL Cursor, which attribute is TRUE when a cursor has some remaining rows to fetch, and FALSE when a cursor has no rows left to fetch?
%FOUND
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Relations produced from an E-R model will always be in
Third normal form
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DBMS → Functional Dependency 2

For which Exception, if a SELECT statement attempts to retrieve data based on its conditions, this exception is raised when no rows satisfy the SELECT criteria?
DUP_VAL_ON_INDEX
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Third normal form is inadequate in situation where the relation
Has multiple candidate keys
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DBMS → SQL Basics 2

In the PL/SQL block below, how many rows will be inserted in the messages table? DECLARE v_start_salesNUMBER := 2; v_end_sales NUMBER := 100; BEGIN FOR i IN v_start_sales..v_end_sales LOOP INSERT INTO messages(msgid) VALUES v_start_sales; END LOOP; END;
99
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If a relation scheme is in BCNF, then it is also in
Third normal form
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DBMS → DDL Commands 2

Which collection types is also known as index-by tables, lets you look up elements Using arbitrary numbers and strings for subscript values?
Associative arrays
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A primary key when combined with a foreign key create
Parent child relationship between the tables that connect them.
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DBMS → DML Commands 2

Assigning a value to a collection element can cause exceptions, such as
All mentioned above
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The set of permitted value for each attribute is called its
Domain
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DBMS → Joins 2

Which is a procedural extension of Oracle- SQL that offers language constructs similar tothose in imperative programming languages?
PL/SQL
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The airline reservation system, the enables are date, flight number, place of departure, destination, type of plane & seats available. The primary key is
Flight number+ date
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DBMS → Views 2

Which of the following retains duplicate rows in the result of a query or in an Aggregate expression?
ALL
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A functional dependency of the form X→Y is trivial if
YC= X
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