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CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
APR2016
ASSESSMENT_CODE MCA3020_APR2016
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
18250
QUESTION_TEXT
What are the differences between Homogeneous and Heterogeneous
Databases?
SCHEME OF
EVALUATION
Homogeneous Databases: When the database technology is the same at
each of the locations and the data at several locations are also
compatible, that data is knows as homogeneous database. Homogeneous
database make the sharing of data between the different users simpler.
This signifies the design goal for the distributed database. Achieving this
objective needs a very high level planning during the planning phase.(1
mark)
The following conditions should exist for homogeneous database:
1.The operating system used at each of the locations is the same or at
least they should be extremely compatible.
2.The data models used at every location should be the same.
3.The database management system used at every location should be the
same or at least they should be extremely compatible.
4.The data at the different locations should have common definitions and
formats.
(4 marks)
Heterogeneous Databases: In heterogeneous DBMS, every one of the
site might manage different types of DBMS wares, which does not need
to be established on the similar original data model and so the system
should be made of RDBMS, OODBMS, and ORDBMS products.(1
mark)
*In heterogeneous database, contact among various DBMS is needed for
translations.
*So as to give database transparency, users should be able to make
requests in DBMS language at the local site.
*Data from other sites might have variety of hardware, diverse DBMS
products and mixture of a variety of hardware and DBMS products.
*The job of finding these data and executing any essential translation are
the capabilities of the heterogeneous DBMS.
(4 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
18251
QUESTION_TEXT
What are the Advantages and Disadvantages of ORDBMS? List the
characteristics of object relational databases.
SCHEME OF
EVALUATION
Advantages of ORDBMS:
1.The main advantage of object relational data model arises from the
concept of “reuse and sharing”, By reuse, we mean that the programmer
can easily extend the DBMS server to achieve the standard functionality
centrally, rather than coding it in each and every application.
2.Sharing means that if the developer wants the applications to use
particular database functionality, then it can be embedded in the
functionality of the server.
3.ORDBMS allows enterprise to easily migrate from their existing
system to an ORDBMS without making major changes.
4.In addition, a user may easily make use of object-oriented systems in
parallel of the RDBMS features.
:[1 Mark x 4 = 4 Marks]
Disadvantages of ORDBMS:
1.The ORDBMS approach is complex in nature and is associated with
increased costs.
2.The Relational database proponents have a view point that the
extensions to relational model in the form of ORDBMS have diluted the
simplicity of relational model which was the major factor behind its
success.
3.Some database experts also believe that the ORDMBS will be of use
for only a limited set of applications which may not be practical for
relational technology.
4.Also the physical architecture of object-relational model is not suitable
for handling high-speed web applications.
[1 Mark x 4 = 4 Marks]
Characteristics of Object Relational Databases:
1.Nested relations.
2.Complex types and object-orientation.
3.Querying with complex types.
4.Creation of complex values and objects.
[any two. one mark each. 1 mark x 2 = 2 marks]
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
18253
QUESTION_TEXT
Explain Temporal Database and Multimedia Database.
SCHEME OF
EVALUATION
Temporal Database: Temporal databases are used to record timereferenced data. Basically, majority of the database technologies are
temporal. For example: Record keeping function (inventory
administration, medical-record and personnel); Financial function
(banking, accounting and portfolio organization); Scientific function
(Weather monitoring), Scheduling function (project organization, hotel,
airline, and train reservations) all these functions trust on temporal
databases. (2 marks)
Temporal databases are best suited for the applications where
information as to organize on time constraints. Therefore temporal
database set a good example to demonstrate the requirement for
development of a combined set of concepts for the use of application
developers. The training of temporal database is designed by application
developers and designers. There are numerous applications where time is
an important factor in storing the information. For example: Insurance,
Healthcare, Reservation Systems, and Scientific Databases. (2 marks)
In case of temporal applications, even the two instances utilized might be
simply expanded. For example, in COMPANY database, it might be
desirable to keep PROJECT, JOB, and SALARY histories of all the
employees. It can be applied to UNIVERSITY database as well, to store
the grade history of STUDENT. The details about the YEAR,
SEMESTER, COURSE and each SECTION are also included in this
database.(1 mark)
Multimedia Database: Multimedia databases facilitate the users to store
as well as generate query for retrieving multimedia information. This
information can demand for: Documents (like articles/books/journals),
Images (like drawings/pictures), Video Clips (like
newsreels/movies/hone videos); Audio clips (like speeches/ phone
messages/ songs).(1 mark)
The primary type of database query generally tries to locate multimedia
sources comprising of particular objects of interest. Such as, one user
wants to locate all the video clips regarding aa specific person, say
Michael Jackson in a video database. Another scenario may be as of
someone willing to retrieve video clips grounded on specific activities
like, video clips where a soccer goal is scored by a certain player or
team. These type of queries are mentioned as content based retrieval, as
they retrieve information bases on a certain activity/object from the
multimedia sources.
(2 marks)
To make this retrieval fast, the multimedia database must make use of
some model to index and manage multimedia sources grounded on the
contents. But identifying the contents of multimedia sources is lengthy
and difficult task. To accomplish this task, two approaches can be
followed as defined below:
1.Based on automatic analysis of the multimedia sources. It is done to
recognize the contents mathematical characteristics.
2.Based on manual identification of the objects and objectives of interest
in each multimedia source. And later on depending on this information
index the sources.
(2 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
73629
QUESTION_TEXT
What are the different models of DBMS? State two advantages of each
type.
SCHEME OF
EVALUATION
5 models with advantages - >2 marks each. Any two advantages among
those mentioned below may be written
Hierarchical
Simplicity (simple design process since data consists of hierarchical
relationship), Security (can execute the changing level of security
characteristics), Database integrity (possible due to inbuilt structure of
parent and child), Relationship handling (proficient for relationships of
the type 1:M)
Network
Simplicity (simple design process since instances of data relationship
occur as N:M type), Flexibility (more flexible as you can navigate data
items in many ways), Standards (include development of worldwide
standards), Relationship handling (proficient for relationships of the
type N:M – popular in real data relationship situations)
Relational
Simplicity simple design process since easy to handle RDBMS), Flexibility
(more flexibity), Follow every mathematical theory (obeys theories in
maths), Relationship handling (can handle any every type of
relationship)
Object relational
Reusability (occurs from reuse and sharing), Flexibility (flexible but not
more flexible than RDBMS), Abstraction (permits developers of
software to incorporate their individual types and techniques applied to
DBMS), Relationship managing (helps in gathering records effortlessly)
Object
Relationship handling (can handle any every type of relationship), Use
of navigational interfaces – hence better than other models
QUESTION_T
DESCRIPTIVE_QUESTION
YPE
QUESTION_ID 73630
QUESTION_T
Discuss any five SQL features in detail.
EXT
5 features - >2 marks each. Any 5 features among those mentioned below
SCHEME OF
EVALUATION may be written
QUESTION_TYP
DESCRIPTIVE_QUESTION
E
QUESTION_ID
125273
QUESTION_TEX
Write a short note on Buffer Management.
T
SCHEME OF
EVALUATION
SQL Server uses buffer pages for any changes or requests for the data on
the database. These buffer pages are 8KB pages on RAM that minimizes
disc Input/Output. Any 8KB page can be buffered in memory, and set of
all pages currently buffered is called as buffer cache. The amount of
memory available to SQL Servers decides how many pages will be cached
in memory. The buffer cache is managed by Buffer Manager. Either
reading from or Writing to any page on the disc happens at two levels. The
data that should be either read/Written is first copied to the buffer cache
and the read/write operation is carried out on the data that is currently on
the Buffer Cache. The edited data is updated on the disc by the buffer
manager only if the in-memory cache has not been referenced for some
time. While writing pages back to the disc, asynchronous I/O is used
whereby the I/O operation is done in a background thread so that other
operations do not have to wait for the I/O operation to complete. Each
page is written with a checksum while they are written to the disc so that
while the data is referred back any time, the checksum mismatch would
detect the corruption of the data.
Data must be in RAM for DBMS to operate on it!
Buffer Mgr hides the fact that not all data is in RAM
Bufferpool information table contains: <frame#, pageid, pin_count,
dirty>
If requested page is not in pool:
Choose a frame for replacement.
Only “un-pinned” pages are candidates!
If frame is “dirty”, write it to disk
Read requested page into chosen frame
Pin the page and return its address
Requestor of page must eventually unpin it, and indicate whether page has
been modified:
dirty bit is used for this.
Page in pool may be requested many times,
a pin count is used.
To pin a page, pin_count++
A page is a candidate for replacement iff pin count == 0 (“unpinned”)
CC & recovery may entail additional I/O when a frame is chosen for
replacement.
Write-Ahead Log
protocol;
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10mark