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1. Database Systems Introduction to Databases

2. 2 Database Management S y stem (DBMS) DBMS is a software package that enables user to create and maintain databases. It facilitates: Defining a database that involves specifying the data types, structures, and constraints for the data to be stored in the database. Constructing a database which is the process of storing the data. Manipulating a database such as functions of querying and sharing the database objects, updating the database, and generating reports from the data. Database and DBMS software together constitute a database system .

3. 1 -3 Examples DBMS Oracle IBM DB2 Ingress Teradata MS SQL Server MS Access MySQL etc.

4. Database Management System (DBMS) Features A Software Package that enables users to define, create, maintain, and control access to the database. Data Definition Language (DDL) Data Manipulation Language (DML) Control access: Security, integrity, concurrent access, recovery, support for data communication, etc. Utility services File import/export, monitoring facilities, code generator, report writer, etc. Support Ad Hoc queries 4

5. Form Processing & Report Processing Applications are build by using VB, DOT Net or PHP programming. Reports can be developed using Crystal Reports tool. Query Processing can be managed by using vendors SQL tool or 3 rd party tools such As TOAD, SQL Developer 5 DBMS Architecture

6. Data Accessing using DBMS 2-tiers & 3-tiers Architectures 6

7. Database Management System DBMS manages data resources like an operating system manages hardware resources A software system that is used to create, maintain, and provide controlled access to user databases Order Filing System Invoicing System Payroll S ystem DBMS Central database Contains employee, order, inventory, pricing, and customer data 7

8. Database System Environment 8

9. 9 DBMS Benefits Minimal data redundancy Consistency of data Integration of data Sharing of data Ease of application development Uniform security, privacy and integrity controls Data accessibility and responsiveness Reduced program maintenance Data independence

10. 1 - 10 DBMS related Applications SQL Forms/ Reports Web/ Portal GUI Client-Server (VB, C++, Java, Mobile) SAP/ OracleApps BI Applications (SAS, OracleWarehousing) Case Tools (Toad Modeler, Enterprise Architect, VISIO etc)

11. Components of DBMS Environment 11

12. Components of DBMS Environment 12 Hardware Can range from a PC to a network of computers Software DBMS, operating system, network software (if necessary) and also the application programs Data Used by the organization and a description of this data called schema

13. Components of DB Environment … 13 Procedures – Instructions and rules that should be applied to the design and use of the database and DBMS People

14. Database Professionals 14 Database implementers Build modules that go inside the DBMS Database application developers Build application that run on top of the DBMS, and are used by end-users to interact with their data. Database Administrators Create database schema Maintain and tune the DBMS engine Maintain and tune the data in the DBMS Corporations need them ($$$)

15. Roles/ Jobs in the Database Environment 15 Data Administrator (DA) Database Administrator (DBA) Database Designers (Logical and Physical) Applications Programmer Database Developer Database Analyst End users (Naive and sophisticated)

16. Forms & Reports 16

17. Interaction of DBMS with Files 17

18. Evolution of DB Systems 18

19. Databases are often represented through the three-schema architecture or ANSI-SPARC architecture. The goal of this architecture is to separate the user application from the physical database. The ANSI / SPARC architecture is claimed to be based on the data organization. 19 Database Schema

20. internal view: It describes the physical structure, details of internal storage and access paths for the database, that of the system or machine conceptual view: It describes the structure of the whole database while hiding the details of physical storage of data that of the enterprise. external view: It describes the portion of a database relevant to a particular user or a group of users while hiding the rest of database. which is that of the user, who might be a programmer; For each of these views, an appropriate schema definition is required. 20 ANSI / SPARC ARCHITECTURE

21. 21 DBMS STANDARDIZATION ANSI / SPARC ARCHITECTURE

22. At the lowest level of the architecture is the internal view , which deals with the physical definition and organization of data. At the other extreme is the external view , which is concerned with how users view the database. Between these two ends is the conceptual schema , which is an abstract definition of the database. It is the “real world” view of the enterprise being modeled in the database. 22 DBMS STANDARDIZATION ANSI / SPARC ARCHITECTURE

23. EMP( ENO , ENAME, TITLE, SAL, PNO , RESP, DUR) PROJ ( PNO , PNAME, BUDGET ) Underlined attributes are relation keys (tuple identifiers). Tabular form Relation Schemes ENO EMP ENAME TITLE PROJ PNO PNAME BUDGET SAL PNO RESP DUR

24. Example Relation Instances