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Monday, December 9, 2013

Environment of DBMS | Database Management system ( DBMS ) Tutorial

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Environment of DBMS :-

Database Management system ( DBMS ) Tutorial

In this section, we examine all the component of the DBMS environment. We can identify five major components in the DBMS environment: hardware, software, data, procedures, and people.
DBMS means Database Management system. It deals with handling and assembling data into database properly. Here we have complete Database Management system ( DBMS ) Course. The DBMS is the software that interacts with the users' application programs and the database. the Database Management system ( DBMS ) is an extremely powerful and useful tool. However, as the end-users are not too interested in how complex or easy a task is for the system, it
could be argued that the DBMS has made things more complex because they now see more data than they actually need or want.
https://www.youtube.com/watch?v=9fiAlM71Fa4

Deterministic Finite Automata ( DFA ) construction with Examples and solution

8:02 PM Unknown 1 comment

Deterministic Finite Automata or DFA construction method is described in this tutorial with an example.
A deterministic finite state automaton (DFA) is a simple language recognition device. It can be seen as a machine working to give an indication about strings which are given in input or it can be given a mathematical definition.
Strings are fed into the device by means of an input tape, which is divided into squares, each one holding one symbol. The main part of the machine itself is a black box which is, at any specified moment, in one of a finite number of distinct internal states, among which we distinguish an initial state and some final states. This black box, called the finite control, can sense what symbol is written at any position of the input tape by means of a movable reading head. Initially, the reading head is placed at the leftmost square of the tape and the finite control is set in a designated initial state.

Second Part of the video

ER Diagram Example | Entity Relationship Diagram Examples

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An Entity Relationship Diagram (ERD) or ER diagram is the best visual representation of a Database. Any Database Designer will follow Entity Relationship Diagram to design physical database. An Entity-Relationship diagram (ERD) typically serves as the main deliverable of a conceptual data model. While newer approaches to E-R modeling have developed, the E-R approach is still cited by some professionals as "the premier model for conceptual database design". An ERD is a logical representation of an organization's data, and consists of three primary components:

Entities -- Major categories of data and are represented by rectangles
Attributes -- Characteristics of entities and are listed within entity rectangles
Relationships -- Business relationships between entities and are represented by lines
An Entity is a person, place, object, event, or concept that an organization wants to maintain data on. Each entity has a unique identity that differentiates it from other entities. A point of distinction must be made between entity types and entity instances. An entity type is a collection of entities that share common properties. Entity types are also known as entity classes. An entity instance is an individual occurrence of an entity type. A data model describes an entity type only once; however there may be numerous instances of that type within a database.

Lets take an example and solve it using ER diagrams :

This above ER diagram example describe this problem:

A publishing company produces books on various subjects. The books are written by authors who specialize in one particular subject. The company employs editors who, not necessarily being specialists in a particular area, each take sole responsibility for editing one or more book publications. Every book require some items for publication. These items supplied by suppliers. One supplier can supply many items. Shop owner buys books from the publisher. Shop owner can buy many books but one book can be bought by one shop owner only. Books are uniquely identified by Bookid.

Database management System Tutorial : Introduction

6:15 PM Unknown 2 comments

DBMS means Database Management system. It deals with handling and assembling data into database properly. Here we have complete Database Management system ( DBMS ) Course. The DBMS is the software that interacts with the users' application programs and the database. the Database Management system ( DBMS ) is an extremely powerful and useful tool. However, as the end-users are not too interested in how complex or easy a task is for the system, it

could be argued that the DBMS has made things more complex because they now see more data than they actually need or want.DBMS for a personal computer
may not support concurrent shared access, and it may provide only limited security,
integrity, and recovery control.
However, modern, large multi-user DBMS products offer
all the above functions and much more. Modern systems are extremely complex pieces
of software consisting of millions of lines of code, with documentation comprising many
volumes. This is a result of having to provide software that handles requirements of a
more general nature.
Furthermore, the use of DBMS nowadays requires a system that
provides almost total reliability and 24/7 availability (24 hours a day, 7 days a week), even
in the presence of hardware or software failure. The DBMS is continually evolving and
expanding to cope with new user requirements. For example, some applications now
require the storage of graphic images, video, sound, and so on. To reach this market, the
DBMS must change. It is likely that new functionality will always be required, so that the
functionality of the DBMS will never become static.