Which of the following ensures the atomicity of the transaction?
Transaction management component of DBMS
Application Programmer
Concurrency control component of DBMS
Recovery management component of DBMS
Correct Answer :
A. Transaction management component of DBMS
Related Questions
For correct behaviour during recovery, undo and redo operation must be
Commutative
Associative
idempotent
distributive
______is a preferred method for enforcing data integrity
Constraints
Triggers
Stored procedure
Cursors
In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect :
Operationally, if Y is deleted, so is X
existence is dependent on Y.
Operationally, if X is deleted, so is Y.
Operationally, if X is deleted, & remains the same.
Which of the following is not a characteristic of a relational database model?
Table
Tree like structure
Complex logical relationship
Records
Key to represent relationship between tables is called
primary key
secondary key
foreign key
none of the above
Which of the following is not a consequence of concurrent operations?
Lost update problem.
Update anomaly.
Unrepeatable read.
Dirty read.
Which of the following ensures the atomicity of the transaction?
Transaction management component of DBMS
Application Programmer
Concurrency control component of DBMS
Recovery management component of DBMS
An advantage of views is
Data security
Derived columns
Hiding of complex queries
All of the above
In multiple granularity of locks SIX lock is compatible with
IX
IS
S
SIX
E-R Modeling is achieved by using ____ diagrams
DFD
Flowcharts
Gantt Charts
E-R
If the closure of an attribute set is the entire relation then the attribute set is a
superkey
candidate key
primary key
not a key
If an entity can belong to only one lower level entity then the constraint is
disjoint
partial
overlapping
single
The ____ operator joins two or more conditions and displays rows only if that rows data satisfies all conditions specified.
OR
AND
NOT
ALL
_______ product was acquired by Informix, integrated into its RDBMS and introduced as the Informix Universal Server an ORDBMS.
Star
llustar
SQL
Cygnus
Consider the join of relation R with a relation S. If R has m tuples and S has n tuples, then the maximum and minimum size of the join respectively are
m+n and 0
m+n and |m-n|
mn and 0
mn and m+n
A _____ is used to define overall design of the database
code
data definition language
application program
schema
SQL server stores index information in the _____system table
system indexes
syst indexes
sys indexes
sysind
______is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
Domain Integrity Constraints
Referential Integrity Constraints
Domain Constraints
Entity Integrity Constraints
Processed data is called _____
Raw data
Source
Information
Useful data
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
A logical schema
is the entire database
Describes how data is actually stored on disk.
is a standard way of organizing information into accessible parts.
All of the above
The ______ key of a relation is the attribute (column) or collection of attributes, which uniquely identify a given tuple.
Primary
Foreign
Candidate
Alternate
………………… 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
The graphical representation of a query is .
B-Tree
graph
Query Tree
directed graph
The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
m - 1
m + 1
m * m
m
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
In an E-R diagram double lines indicate
Total participation.
Multiple participation.
Cardinality N.
None of the above.
What are the desirable properties of a decomposition
Partition constraint.
Dependency preservation.
Redundancy.
Security.
What is a disjoint less constraint?
It requires that an entity belongs to no more than one level entity set.
The same entity may belong to more than one level.
The database must contain an unmatched foreign key value.
An entity can be joined with another entity in the same level entity set.
The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
Fields
Records
Relations
Keys