What is RDBMS Lecture -4

What is RDBMS

DBMS:-

                    Data base management system (DBMS) which follows all the 12 rule given by  Dr Edgar F. Codd  known as Relational data base management system (RDBMS)

According to Dr.Edgar F codd rule are as follows

1 Information Rule :- 

                                        This rule states that all information (data) ,which stored in database must be stored in table  formats,this information can be user data or meta -data.

2.Guaranteed Access rule :-

                                        This rule states that every single data element (value) is guaranteed to be accessible logical with combination of table name and primary key .

3.Systematic Treatment of NULL value:-

                      This rule states that NULL value in the database must be given systematic treatment i.e. primary key value never be NULL because NULL have several meaning that cause various anomaly occurs in data base

4.Active online catalog :-

                                      This rule states that the structure of whole database must be stored  in an online catalog i.e. Data Dictionary

5. Comprehensive data sub-language rule :-

                                     This rule states that  database must have support for a language which has linear syntax which is capable of Data Definition ,Data Manipulation,Data control  

6.View Updating rule:-

                               This rule states that all system should able to updates all views of database  without any anomaly in the system

7. High-level insert -Update and Delete rule:-

                               This rule states that system must support high level insertion,updation ,deletion this must not be limited to a single row that it must support join operations to yield set of data

8. Physical data independence:-

                              This rule states that application should not have any concern about ,how the data physically stored in the system as well as any change in physical structure must not have any impact on application 

9.Logical Data Independence:-

                            This rule states that logical data must be independent of its user's view as well as any change in logical data must not imply any change in the application .e.g. if two table are merged or one is split into two different table there should be no impact on the application

10.Integrity Independence:-

                               This rule states that all integrity constraints can be independently modified without the any change in the application.this rule makes database independent of front-end application and its interface.

11.Distribution Independence:-

                      This rule states that the end user must not be able to see that the data in distributed over various locations,end user have feel that data is located at one site only. 

12. Non-subversion rule:-

                              This rule states that if system has an interface that provides access to low level records ,this interface then must not be able to subvert the system and bypass security and integrity constraint 

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DBMS Data Independence Lecture -3

 Data Independence 

Data independence can be define as the capacity to change the schema at one level of data base system without having to change the schema at higher level .data independence further classified into to category as follow

1.Logical Data Independence

2.Physical data Independence

Logical data Independence:- 

                                            The capacity to change the conceptual Schema without having to change the external schema or users programs

Physical data Independence:-

                                                  The capacity to change the the internal Schema without having to change the conceptual schema

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Database Management system (Advantage of DBMS over flat file system) Lecture -2

Advantage of DBMS over flat file system

1. Easy to Access [ By Indexing ]

2.Gives less I/O task to Access data 

3. It gives more concurrency level

4.More Security over the data File [By providing Views]

5. Data Independence [By providing three level Interdependency]

6.Data Integrity and Security

7.Data Administration

8.concurrent Access and crash recovery 

9.Control Redundancy [Duplication  of data]

10.Reduced Application Development time [By providing Higher level Interface]

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Data Base Management System Made easy class room note Lecture -1

Data Base Management System Made easy class room note  Lecture -1

DBMS syllabus and reference for GATE 

Databases:   

              Relational model (ER-model, relational algebra, tuple calculus), Database design (integrity constraints, normal forms), Query languages (SQL), File structures (sequential files, indexing, B+ trees), Transactions and concurrency control;

Reference Book:-

   Database Management systems  –>   Raghu RamaKrishnan
   Database system concepts  – > Silberschatz , Korth , Sudarshan
   Database systems   – >    C.J.Date (Normalisation is very lucidly written )
   Principles of Database Systems – > J.D.Ullman  (This is a very good book )

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 Note:-

As per analysis of GATE previous years papers  found that all the topics of the above syllabus are important so i suggest you go through all the topic but as per previous GATE paper experience probability of occurring question are more from -Normalization,normal form relation algebra, SQL query and transactions and concurrency .

Once you will go through old paper you will find that maximum time 2 question (link question) asked from SQL query only or normalization (normal form) and one marks question from rest of the syllabus so focus on these two topics  so in our lecture we will cover these topic first .

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What is DBMS?

                           Before understand DBMS we understand some basic terminology

Database:-  Database is a collection of related data

Management System:-  A software used to manage the database in efficient way

                DataBase+Management Syatem  =DBMS

DBMS Definition:-  Database is a computer base record keeping system and the way through which we manage the system known as management system

DBMS Definition by Korth:-

                                       A Database management system is a collection of interrelated data and set of programs to access these data.

DBMS Defination by Ullman:-

                                      DBMS is powerful tool for creating and managing large amount of data efficiently and allowing it to persist over long period of time.

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Introduction of Java Programming (Basic Introduction) Lect-1

Introduction of Java Programming 

Key Note :-

• Before start Java programming you have to understand that how to learn java ,what strategy required to learn java because there are lot of book available in market/Internet for java which only provides you content but no book tell us that how to start /how to read /what are the right track for learning java programming 

• Second point which comes in your mind that to learn  java what kind of programming background required i.e. whether C/C++ mandatory to learn before start java .
• I frankly tell you that for java there is no need of background knowledge of C/C++,but if know its fruitful for you.

• The next  thing comes to your mind that why Java where various programming language available in the market?

•  Java is Almost pure object oriented /platform independent   programming language.which support concept of WORA(Write once run any where)

• Later on  I  will give many reason why java only

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