PRESENTED BY: SYED SAAD QAISER RELATIONAL DATABASE SYSTEMS

THE CRITERIA OF THE PRESENTATION Explain database systems Database system Features Explain and contrast relational database systems Central concept of relational database system Provide Relational database theory and sql equivalent A Practical implementation Example of relational Database Hypothetical Relational Database Model

DATA BASE SYSTEM A data base system is an overall collection of different data base software components and databases containing the following parts: 1, Database application programs 2, client components 3, databases 4, database servers

DATABASE APPLICATION PROGRAM Database application program: A database application program is a special purpose software that is designated and implemented by users or implemented by third-party software companies

CLIENT COMPONENTS Client components: Client components are general-purpose database software designed and implemented by a data base company. By using Client components, users can access data stored on same or a remote computer.

DATABASE Database: A database has 2 perspectives namely the user and the database system. User view database as a collection of data that logically belongs together. For a database system, a database is simply a series of bytes, stored on a disk. The common ground between the two perspectives is that database system needs to provide not only interfaces that enables users to create databases and retrieve or modify data but also system components to manage the stored data.

DATABASE SERVER Database Server: A Database server manages data stores in a database. Each client communicates with a database server by sending user queries. The server processes each query and sends the results back

DATABASE SYSTEM FEATURES A Data base system must provide following features: Variety of user interface Physical data independence Logical data independence Query optimization Data integrity Concurrency control Database security Backup and recovery.

NOTION “ RELATIONAL DATA BASE”. The notion of relational data base system was first introduced by E.F Codd in his article “ A relational model of Data for large stored Data Banks” in 1970.

RELATIONAL DATABASE SYSTEMS : The data or information are gathered and arranged as a table with ease of accessing or updating the information without a need to re-assemble the entire table or database structure. relational database systems are based upon a strong mathematical background.

CENTRAL CONCEPT OF RELATIONAL DATABASE SYSTEMS: The central concept of relational database system is the “Relation”- that is a table. From the user’s point of view, a relational database contains tables and nothing but tables, which are interrelated in the logical layer of the database.

RELATIONAL DATABASE SYSTEMS An example of relational database system would be Microsoft SQL server component called “Database Engine”

RELATIONAL DATABASE THEORY AND SQL EQUIVALENT Relational database theory uses a set of mathematical terms, which are roughly equivalent to SQL database terminology. The table on the next slide summarizes some of the most important relational database terms and their SQL database equivalents.

RELATIONAL DATABASE THEORY AND SQL EQUIVALENT Relational TermSQL Equivalent Relation, base relvartable Derived relvarView, query result, result set tuplerow attributeColumn name Relational schemeSet of column names Attribute valuedata

PRACTICAL IMPLEMENTATION EXAMPLE OF RELATIONAL DATABASE:

CONT..

PRACTICAL IMPLEMENTATION EXAMPLE OF RELATIONAL DATABASE Table 1 named as ‘Customer_Sales’. A table to store the information related to customer wise sales on each date Table 2 named as ‘Customer Master’ - A table to store the master information of each customer. These two tables are related to each other with the help of the Customer_ID column, thus they form the relational database system. A typical relational database can have from 10 to such related tables.

HYPOTHETICAL RELATIONAL DATABASE MODEL

THE END Thank you for being such a patient audience.