Relational Model | ER to Relational model conversion

ER TO RELATIONAL MODEL CONVERSION

INTRODUCTION- In the E-R model, data is represented using entities, and relationships are defined between these entities. However, with the relational model, the entities and their relationships follow strict guidelines. Usually, an E-R model is first developed, and then it is transformed into a relational model.

RULES TO CONVERT  ER TO RELATIONAL MODEL CONVERSION-

•        Build a table for each entity set
•         Build a table for each relationship set if necessary (more on this later)

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Database management software microsoft access | download microsoft access

Microsoft Access, also known as Microsoft Office Access, is a database management system from Microsoft that combines the relational Microsoft Jet Database Engine with a graphical user interface and software-development tools. It is a member of the Microsoft Office suite of applications, included in the Professional and higher editions or sold separately.

Microsoft Access stores data in its own format based on the Access Jet Database Engine. It can also import or link directly to data stored in other applications and databases.

Software developers and data architects can use Microsoft Access to develop application software, and "power users" can use it to build software applications. Like other Office applications, Access is supported by Visual Basic for Applications, an object-oriented programming language that can reference a variety of objects including DAO (Data Access Objects), ActiveX Data Objects, and many other ActiveX components. Visual objects used in forms and reports expose their methods and properties in the VBA programming environment, and VBA code modules may declare and call Windows operating-system functions.

you can download microsoft access here.
download link:click here

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Database management software informix | download informix

IBM Informix is a product family within IBM's Information Management division that is centered on several relational database management system (RDBMS) offerings. The Informix products were originally developed by Informix Corporation, whose Informix Software subsidiary was acquired by IBM in 2001.

IBM has continued active development and marketing of the key Informix products, the current version of which (12.1) forms the basis of several product editions with variation in capacity and functionality. The Informix database has been used in many high transaction rate OLTP applications in the retail, finance, energy and utilities, manufacturing and transportation sectors. More recently the server has been enhanced to support data warehouse workloads.

The Informix server supports the object-relational model, which has permitted IBM to offer extensions that support data types that are not a part of the SQL standard. The most widely used of these are the time series and spatial extensions, which provide both data type support and language extensions that permit high performance domain specific queries and efficient storage for datasets based around time series and spatial data.

Download informix here.

Download link:click here

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ADABAS software | database software | download ADABAS

ADABAS is Software AG’s database management system (DBMS). ADABAS organizes and accesses data according to relationships among data fields. The relationships among data fields are expressed by ADABAS files, which consist of data fields and logical records.
With the ADABAS DBMS, you can also use the high-level language NATURAL to operate on data that is managed by the DBMS.
Adabas made by Software AG, once was the most powerful mainframe database, now runs in multiple platforms, and provides superior reliability and performance.

Download link:click here

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Teradata database software download teradata

Teradata Corporation is an American computer company that sells analytic data platforms, applications and related services. Its products are meant to consolidate data from different sources and make the data available for analysis. Formerly a division of NCR Corporation, Teradata was incorporated in 1979 and separated from NCR in October 2007.

 Michael Koehler became president and CEO of Teradata after its 2007 spin off from NCR. Teradata's Applications business is led by Darryl McDonald, and the corporate headquarters is located in Miamisburg, Ohio.

Teradata Database, currently on Version 2 Release 6.0, is the most powerful Very Large Database (VLDB) system. Many largge scale data warehousing and business intelligence systems are powered by Teradata.

Download link: click here

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Top 10 database management software | best database management software

Hey guys today i am going to tell you the name of best 10 data base management software using in all over world this time.


Top 10 Database Software Systems

The most powerful database systems running today’s enterprise businesses around the world:

1.Oracle – Oracle Enterprise Server, designed for grid computing, is the best RDBMS, running on multiple platforms, with the latest version 11G.

2.DB2 – DB2 is the database management system that delivers a flexible and cost-effective database platform to build robust on demand business applications. The DB2 Universal Database (UDB) Enterprise Server Edition 7 (ESE) is one of the best RDBMS.

3.SQL Server – Microsoft SQL Server is a comprehensive database software platform providing enterprise-class data management and integrated business intelligence (BI) tools.

4.Sybase – Sybase Adaptive Server Enterprise (ASE) is a high-performance, mission-critical database management system that gives customers an operational advantage by lowering costs and risks
.
5.Teradata – Teradata Database, currently on Version 2 Release 6.0, is the most powerful Very Large Database (VLDB) system. Many largge scale data warehousing and business intelligence systems are powered by Teradata.

6.ADABAS – Adabas made by Software AG, once was the most powerful mainframe database, now runs in multiple platforms, and provides superior reliability and performance.

7.MySQL – A open source database, mySQL is the most popular database for web-based business applications, and is moving to enterprise level.

8.FileMaker – FileMaker Pro 8.5 is the #1-selling easy-to-use database software for Windows and Mac OS. FileMaker Server 8 maximizes performance of shared databases while increasing security.

9.Access -Microsoft Access is the most used desktop database applicaiton in Windows.

10.Informix -Informix, now under IBM, once was the most promised object-oriented database.


if you think my post is wrong then its a request feel free to comment.....

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Third Normal Form (3NF) |Normalization and its type

THIRD NORMAL  FORM(3NF)

INTRODUCTION--

A relation is said to be in third normal form(3NF) if both conditions hold simultaneously.

1.) The relation is in Second Normal Form(2NF)

2.) Non-key attributes of the relation should not be transitively dependent on the primary key.

The main purpose of the 3NF is to remove the transitive dependency which is the main cause of anomalies in the 2NF.

EXAMPLE- To explain the 3NF, let us consider the example of STUDENT relation.Here the primary key is Stu_Id.

Stu_Id	Stu_Name	Teach_Id	Teach_Name	Teach_Qual
2523	Anurag	T001	Navathe	Ph.D
3712	Pankaj	T004	Date	M.Tech
4096	Gagan	T001	Navathe	Ph.D
2716	Anshu	T004	Date	M.Tech
1768	Harman	T009	Desai	M.Tech

The STUDENT relation is in 2NF but it suffers from insertion,deletion,updation anomalies.The main reason of these anomalies is because some attributes are transitively functionally dependent on the primary key.This results in redundancy in the relation.The dependencies that exist in STUDENT relation are:-

Here, the Stu_Name is functionally dependent on the attribute Stu_Id. Also Teach_Id is functionally dependent on the attribute Stu_Id. Also, Teach_Name is functionally dependent on Teach_Id  so we can say that Teach_Name is transitively functionally  dependent on Stu_Id.Similarly, Teach_Qual is transitively functional dependent on Stu_Id attribute.

                   So to make the relation in 3NF, We have to eliminate this transitive dependence on the primary key.To achieve this

1.) Create a new relation from the source relation that contains all the original attributes but without those attributes that are transitively dependent on the primary key.So in case of STUDENT relation,the resulting relation will contains Stu_Id ,Stu_Name and Teach_Id attributes.The primary key in this relation is same as in the original relation i.e. (Stu_Id).

Stu_Id	Stu_Name	Teach_Id
2523	Anurag	T001
3712	Pankaj	T004
4096	Gagan	T001
2716	Anshu	T004
1768	Harman	T009

2.) The other relation created from the source relation will contain attributes that are transitively functionally dependent on the primary key of the original relation plus the non key attribute from the original source relation on which the transitive functional dependent  attributes are functionally dependent. The primary key of the resulting relation will be a non key attribute on which the non key attributes are functionally dependent.

Teach_Id	Teach_Name	Teach_Qual
T001	Navathe	Ph.D
T004	Date	M.Tech
T009	Desai	M.Tech

Now the relation is in 3NF.

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Fourth normal form | normalization and its type

FOURTH  NORMAL FORM(4NF)

A relation is said to be in  fourth normal form, if the following conditions hold.

1.) A relation should be in  BCNF (or 3NF).

2.) It contains no multi-valued dependency.

EXAMPLE- Consider a relation "EMPLOYEE".In this relation all the three attributes act as a primary key since no single attribute can uniquely identify a tuple (record).

Empname	Equipment	Language
Anurag	PC	English
Anurag	PC	French
Anurag	Mainframe	English
Anurag	Mainframe	French
Kapil	PC	English
Kapil	PC	French
Kapil	PC	Japanese

In the above example relationship between Empname and Equipment is a multi-valued dependency.Thus it implies that

Similarly, the relationship between Empname and Language is a multi-valued dependency which is represented as  

So,the relation is not in 4NF .To make it into 4NF we have to remove all the multi-valued dependency.For that move each MVD (Multi-valued dependency)  pair to a new relation having relation names  EMP_GPP and EMP_APP.

Relation EMP_GPP-                                                                      

Empname	Equipment
Anurag	PC
Anurag	Mainframe
Kapil	PC

Relation EMP_APP-

Empname	Language
Anurag	English
Anurag	French
Kapil	English
Kapil	French
Kapil	Japanese

Now it is in 4NF.

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Join Dependency in Database management | Database design

JOIN DEPENDENCY

INTRODUCTION- Join dependency states that after a relation has been decomposed into multiple smaller relations,it must be capable of being joined again on common keys to form the original relation.

EXAMPLE-Consider a relation "PRO"

FACTORY	COMPONENT	PROJECT
GM	Engine	MPC
GM	Gear box	125A
Honda	Engine	125A
GM	Engine	125A

Now decompose this relation into two parts-first part is A1 and second part is A2.

Relation A1

FACTORY	COMPONENT
GM	Engine
GM	Gear box
Honda	Engine

Relation A2

COMPONENT	PROJECT
Engine	MPC
Gear box	125A
Engine	125A

Now again combine these two relations and check either we get the original relation or not. The relation after recombine is

FACTORY	COMPONENT	PROJECT
GM	Engine	MPC
GM	Gear box	125A
Honda	Engine	125A
GM	Engine	125A
Honda	Engine	MPC

Now here we can see that after recombine the relation, we could not get the original relation.An extra tuple is added to the relation which is Honda,Engine,MPC. So, this relation does'nt hold Join dependency.

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Fifth normal form in Database management system | Normalization and its type

FIFTH NORMAL FORM-

DEFINITION- A table is in fifth normal form (5NF) or Project-Join Normal Form (PJNF) if
1. It is in 4NF 
2. It cannot have a lossless decomposition into any number of smaller tables. 

EXAMPLE- Consider a relation as an example of a buying table.This is used to track buyers, what they buy, and from whom they buy.

Buyer	Vendor	Item
Sally	Liz Claiborne	Blouses
Mary	Liz Claiborne	Blouses
Sally	Jordach	Jeans
Mary	Jordach	Jeans
Sally	Jordach	Sneakers

Problem:- The problem with the above table structure is that if Claiborne starts to sell Jeans then how many records must you create to record this fact? The problem is there are pair wise cyclical dependencies in the primary key. That is, in order to determine the item you must know the buyer and vendor, and to determine the vendor you must know the buyer and the item, and finally to know the buyer you must know the vendor and the item.

Solution:- The solution is to break this one table into three tables; Buyer-Vendor, Buyer-Item, and Vendor-Item. So following tables are in the 5NF.

Relation Buyer-Vendor-

Buyer	vendor
Sally	Liz Claiborne
Mary	Liz Claiborne
Sally	Jordach
Mary	Jordach

Relation Buyer-Item-

Buyer	Item
Sally	Blouses
Mary	Blouses
Sally	Jeans
Mary	Jeans
Sally	Sneakers

Relation Vendor-Item-

Vendor	Item
Liz Claiborne	Blouses
Jordach	Jeans
Jordach	Sneakers

These relation are in 5NF.

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