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CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
OCTOBER15
ASSESSMENT_CODE BT0066_OCTOBER15
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
4499
QUESTION_TEXT
Explain various storage devices and their characteristics.
SCHEME OF
EVALUATION
1.Cache: The cache is the fastest and most costly form of storage. Cache
memory is small; its use is managed by computer system hardware. We
shall not concern about managing cache storage in the database system.
2.Main memory: The storage medium used for data is available to be
operated on is main memory. The general purpose machine instructions
operate on main memory. Although main memory may contain many
megabytes of data, it is generally too small for storing the entire
database. The contents of main memory are usually lost if a power
failure or system crash occurs.
3.Magnetic–disk storage: The primary medium for the long-term on-line
storage of data is the magnetic disk. Usually the entire database is stored
on magnetic disk. The system must move the data from disk to main
memory so that they can be accessed. After the system has performed the
designated operations, the data that have been modified must be written
to disk.
4.Flash memory: It offers from main memory in that data survive power
failure. Reading data from flash memory takes less than 100
nanoseconds which is roughly as fast as reading data from main
memory. It is also known as erasable programmable read only
memory(EEPROM)
5.Optical storage: The most popular forms of optical storage are the
compact disks (CD) which can hold about 640 megabytes of data and the
digital video disk (DVD) which can hold about 4.7 or 8.5 gigabytes of
data per side of the disk. Data are stored optically on a disk and are read
by a laser. The optical disks in read only compact disks (CD-ROM) or
read only digital video disk (DVD-ROM) cannot be written but are
supplied with data prerecorded.
6.Tape storage: Tape storage is used primarily for backup and archival
data. Although tape is much cheaper than disks access to data is much
slower, because the tape must be accessed sequentially from the
beginning. For the reason tape storage is referred to as direct access
storage because it is possible to read data from any location on disk.
(Any five Storage devices, 2x5=10 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
73048
QUESTION_TEXT
Explain magnetic disks along with its physical characteristics,
performance measures & optimization of disc block access.
Magnetic Disks
The magnetic disks facilitate the bulk of secondary storage. In the
modern computer systems the storage capacity requirements have been
growing at over 50 percent per year.
Physical Characteristics of Disks
SCHEME OF
EVALUATION
Each disk platter has a flat circular shape. Its two surfaces are covered
with a magnetic material, and information is recorded on the surfaces.
Platters are made from rigid metal or glass and are covered (usually on
both sides) with magnetic recording material. The disk surface is
logically divided into tracks, which are subdivided into sectors. A
sector is the smallest unit of information that can be read from or written
to the disk.
Performance Measures of Disks
The quality of a disk can be measured by its access time, capacity,
reliability and data-transfer-rate.
Access time is the time from when a read or write request is issued to
when data transfer begins.
4 Optimization of Disk-Block Access
In most of the operating system the disk I/O request generated by file
system and by virtual memory manager. Here the request provides
address on the disk and this address is in the form of a block number. A
block is a contiguous sequence of sectors from a single track of one
platter.
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
73050
QUESTION_TEXT
Explain embedded SQL & explain embedded SQL statements.
SCHEME OF
EVALUATION
6 Embedded SQL
So far we treated SQL as independent language and also various types of
SQL query construct. There is an interactive interface for relational
DBMS, which facilitate many users to enter SQL commands
directly. This approach is fine as long as the tasks which need to be
performed purely on SQL commands. There are few situation arises
where we require these languages beyond the data manipulation only…
Embedding SQL Statements
A host program can have any number of SQL statements provided it
must be clearly marked and details about these statements. In C, EXEC
SQL is pre-fixed to SQL statements. We can place SQL statement can
appear any place in the host program.
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118244
QUESTION_TEXT
What are the update statements used in database? Explain.
Insert
Delete
SCHEME OF EVALUATION Update (1 mark)
Explain each with example 3*3=9 marks
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118249
QUESTION_TEXT
Discuss the various Normal forms of a relation.
●
1NF
●
2NF
●
3NF
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4NF
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5NF
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BCNF (10 marks)
SCHEME OF EVALUATION
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
163209
QUESTION_TEXT
List and explain the relational database components.
Relational database components include:

Table

Row
SCHEME OF EVALUATION 
Column

Field

Primary key

Foreign key