Saturday, 3 December 2016

10 Previous Year Questions Of DBMS

1)A set of programs that handle firm's database responsibilities is called a
a)Database Management System(DBMS)
b)Database Processing System(DBPS)
c)Data Management System(DMS)
d)All of the above
e)None of these

2)Which of the following is used with database?
a)EDI
b)Credit card
c)ATM
d)Payment Gateway
e)Data mining

3)In Oracle, who owns the data dictionary?
a)Oracle
b)SYS
c)The DBA
d)System
e)None of these

4)The language used in application programs to request data from the DBMS is referred to as the
a)DML
b)DDL
c)Query Language
d)DCL
e)None of these

5)An indexing operation 
a)Sorts a file using a single key
b)Sorts file using two keys 
c)Establishes an index for a file
d)Both a and c
e)None of these

6)In SQL, which command is used to changes data in a data table?
a)Update
b)Insert
c)Browse
d)Append
e)None of these

7)An Oracle server index........
a)Is a schema object
b)Is used to speed up the retrieval of rows by using a pointer
c)Is independent of the table it indexes
d)All of the above
e)None of these

8)Aggregation is special form of ........
a)Object
b)Specialization
c)Generalization
d)Association
e)None of these

9)Which command is used to redefine a column of the table in SQL?
a)Alter Table
b)Modify Table
c)All of the Above
d)Define Table
e)None of these

10)Data mining evolve as a mechanism to cater the limitations of ..........system to deal massive data sets with high dimensionality, new data type, multiple heterogenous data resources etc.
a)OLTP
b)OLAP
c)DSS
d)DWH
e)None of these



Answers:
1)d
2)e
3)b
4)c
5)a
6)a
7)d
8)c
9)a
10)a

Introduction of DBMS Part-2



Data Independence in DBMS:
Upper level are unaffected by changes in lower level.

Two Types of Data Independence:

a)Physical Data Independence:

  • Physical storage structure or devices can be changed without affecting conceptual schema.
  • Modification done to improve performance.
  • It provide independence to conceptual schema and external schema


b)Logical Data Independence:

  • Conceptual schema can be changed without affecting external schema.
  • Structure of database is altered when modification done in conceptual schema.
  • It provide independence to external schema.


DBMS Components:
1)Hardware

  • Processor/main memory(used for execution)
  • Secondary Storage devices(for physical storage)

2)Data
3)Software
4)Users
5)Procedures(Set of rules for database management)

Types of Users:

a)Naive Users:
End Users of the database who work through menu driven application programs, where the type and range of response is always indicated to the users.

b)Online Users:
Those users who may communicate with database directly through an online terminal.

c)Application Programmer:
Those users who are responsible for developing the application program.

d)DBA(Database Administrator)


DBA(Database Administrator):
DBA directs or performs all activities related to maintaining a successful database environment.

Function of DBA:

  • Defining Conceptual Schema
  • Physical Database Design
  • Tuning database performance
  • Security and Integrity Check
  • Back up and Recovery Strategies
  • Improving query processing performance
  • Granting User Access


Database Languages:

1)DDL(Data Definition Language):

  • Deals with database schemas and description, how the data should reside in the database.
  • Used to alter/modify a database or table structure and schema.

Command used in DDL:

  • Create
  • Alter
  • Drop
  • Rename
  • Truncate
  • Comment


2)DML(Data Manipulation Language)

  • Deals with data manipulation
  • These statements afffects records in a table.

Command used in DML:

  • Update
  • Select
  • Insert
  • Delete
  • Merge
  • Call
  • Lock Table


Two Types of DML:
a)Procedural DML(How data is fetch)
b)Non-Procedural DML(What data is to be fetch)

3)DCL(Data Control Language)
Control the level of access that users have on database objects.
Command used in DCL:

  • Grant 
  • Revoke


4)Transaction Language:
Control and manage transactions to maintain integrity of data within SQL statement.
Command used in Transaction Language:

  • Set Transaction
  • Commit
  • Savepoint
  • Rollback


Thursday, 1 December 2016

Indian Post Payment Bank Admit Card Out



India Post Payments Bank (IPPB)  has released the call letter of Officers Scale II, III and V. Exam will be conducted on 17th December 2016.




http://ibps.sifyitest.com/ippboff3sep16/cloea_nov16/login.php?appid=2c5617b4e43cb0f875d681a814990d66

Introduction of DBMS



Data: Facts, figures, statistics etc.

Record: Collection of related data items.

Table or Relation: Collection of related records.

Database: Collection of related relation/data. In database, data is organized strictly in row and column format.The columns are called FieldsAttributes or Domains. The rows are called Tuples or Records.

Features of Data In a Database:

1)Security
2)Consistency
3)Non-Redundancy
4)Shared
5)Independence
6)Persistence

DBMS(Database Management System)It is software that allows creation, definition and manipulation of database.l It is middle layer between data and program.

File System:
  • Stores permanent records in various files
  • Need application program to access and manipulate data.

Disadvantage of File System:
  • Data Redundancy
  • Data Inconsistency
  • Difficult in accessing data
  • Data Integrity
  • Low Security
Data Abstraction:To simplify the interaction of users and database, DBMS hides some information which is not user interest is called Data Abstraction. So, developer hides complexity from users and show Abstract view of data.

DBMS Architecture/3-Tier Architecture:

1)External/View Level:It is user's view of the database.This level describes the part of the database that is relevant to each user.

2)Conceptual/Logical Level:
  • Describes what data is stored in the database and the relationship among the data.
  • Represent all entities, their attributes and their relationship
  • Constraints on the data
  • Security and Integrity information


3)Physical/Internal Level:

  • Describes how the data is stored in the database
  • Storage Space allocation for data and indexes
  • File System
  • Data compression and Data encryption techniques
  • Record Placement
Schemas: 
  • It is overall description of the database.In three-level architecture, one schema at each level.
  • Does not specify relationship among files.


Instances:
Collection of information stored in the database at a particular moment.

Sub-schema:It is a subset of schema and inherits the same property that the schema has. It is an application programmer's or user view of the data items types and record types which he or she uses.

Tuesday, 29 November 2016

LIC AAO Recruitment 2017 Notification Out Soon

 ...........NOTIFICATION WILL OUT SOON..........

Name of post: Assistant Administrative Officer – AAO (Generalist) 
Vacancies for SC category: 86 
Vacancies for ST category: 43 
Vacancies for OBC category: 182 
Vacancies for UR category: 339 
Total number of vacancies: 650

Age criteria: The minimum age of the candidates as on December 1, 2016 should be 21 year while the maximum age should be 30 years. The age relaxation limit for the SC/ST category is five years, three years for OBC category, 10 years for PwD (General) category, 15 years for PwD (SC/ST) category and 13 years for PwD (OBC) category. Other age relaxation rules are as applicable.