Relationships among relationships can be represented in an-E-R model using
Aggregation
Association
Weak entity sets
Weak relationship sets
Correct Answer :
A. Aggregation
Related Questions
As per equivalence rules for query transformation, selection operation distributes over
Union.
Set difference.
Intersection.
All of the above.
_____ is a utility to capture a continuous record of server activity and provide auditing capability.
SQL server Profile
SQL server wizard.
SQL server service manager
SQL server setup
Which of the following concurrency control schemes is not based on the serializability property?
Two - phase locking
Graph-based locking
Time-stamp based locking
None of these .
In SQL the word natural can be used with
inner join
full outer join
right outer join
all of the above
If a transaction T has obtained an exclusive lock on item Q, then T can
read Q
write Q
both read and write Q
write Q but not read Q
The cost of reading and writing temporary files while evaluating a query can be reduced by
building indices
pipelining
join ordering
none of the above
For using a specific database …………… command is used.
use database
database name use
Both A & B
None of them
Immediate database modification technique uses
Both undo and redo.
Undo but no redo.
Redo but no undo.
Neither undo nor redo.
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by
jamming
password
documentation
record lock
Which one is true statement :
With finer degree of granularity of locking a high degree of concurrency is possible.
Locking prevents non-serializable schedules.
Locking cannot take place at field level.
An exclusive lock on data item X is granted even if a shared lock is already held on X.
For correct behaviour during recovery, undo and redo operation must be
Commutative
Associative
idempotent
distributive
An outstanding functionality of SQL is its support for automatic_____ to the target data.
programming
navigation
functioning
notification
Which is the best file organization when data is frequently added or deleted from a file?
Sequential
Direct
Index sequential
None of the above
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
In SQL, testing whether a subquery is empty is done using
DISTINCT
UNIQUE
NULL
EXISTS
A _____ is a logical unit of database processing that includes one or more data access operations that can include insertion, deletion, modification or retrieval operations.
Database
Data
Transaction
Record
Which of the following is not a consequence of non-normalized database?
Update Anomaly
Insertion Anomaly
Redundancy
Lost update problem
In an ER diagram the ___shape specifies the Attibute and a ____ shape specifies the primary key attribute.
Oval; An oval with an underlined attribute
Circle; A circle with bolded attribute inside it
Diamond; A bolded attribute
Square; An attribute within the square
E-R Modeling is achieved by using ____ diagrams
DFD
Flowcharts
Gantt Charts
E-R
A relation is in attribute of other composite key. if an attribute of a composite key is dependent on an
2NF
3NF
BCNF
1NF
The _____ category includes storage media that can be operated on directly by the computers central processing unit.
Primary storage
Secondary Storage
All
Tertiary Storage
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
………………… approach reduces time and effort required for design and lesser risk in database management.
Single global database
Multiple databases
Top-down approach
None of the above
Which of the following is not a property of transactions?
Atomicity
Concurrency
Isolation
Durability
____specifies a search condition for a group or an aggregate.
GROUP BY Clause
HAVING Clause
FROM Clause
WHERE Clause
operator is used to compare a value to a list of literals values that have been specified.
Like
COMPARE
BETWEEN
IN
The _______ is a set of programs to use and / or modify this data.
DBMS
System
Program
Software
A ____ key specifies a uniqueness constraint that no two distinct tuples in any state r of relation R can have the same value for super key.
Sub
Parent
Candidate
Super
In b-tree the number of keys in each node is than the number of its children.
one less
same
one more
half