Introduction1. It is a software package with computer programs that control the creation, maintenance, and the use of a database.2. Collection of interrelated data.3. Set of programs to access data.
History• In 1977, computer programmers Larry Ellison and Robert Miner co-founded Oracle Systems Corp.• In 1983, Oracle developed the first portable RDBMS, which allowed firms to run their DBMS on various machines including mainframes, workstations, and personal computers.• Soon thereafter, the firm also launched a distributed DBMS, based on SQL-Star software.
Components of DBMS• Data definition subsystem• Data manipulation subsystem• Data administration subsystem• DBA (Database Administrator)• Database user• Hardware
Features of DBMS• Accept data input & store• Multi-user access• Security• Query languages (searching, sorting)
Data Models1. Data model: A way to design a dbase or describe a database2. Data modeling: Process of creating a data model3. Data Models the hierarchical model the network model the relational model the multidimensional model, and the object model
Hierarchical Model• Data or records are organized in a hierarchy manner.• Used to present the hierarchy of an organization.
Network Model• It is an extension of hierarchal model• In this model, data elements of a database are organized to have parent -child relationship
Relational Model• A database in which relations between information items are explicitly specified as accessible attributes.• Data are stored or organized in tables.
Multidimensional Model• It is a variation of the relational model that uses multidimensional structures to organize data and express the relationships between data.
Object Model• It is a database management system in which information is represented in the form of objects as used in Object-Oriented Programming.
Applications Of DBMS• Banking: For customer information, accounts loans and banking transactions.• Airlines: For reservations and schedule information.• Universities: For student information, course registrations and grades.• Credit card transactions: For purchases on credit cards and generation of monthly statements.• Telecommunications: For keeping records of calls made, generating monthly bills,etc..
Contd..• Finance: For storing information about holdings, sales and purchase of financial instruments such as stocks and bonds.• Sales: For customer, product and purchase information.• Manufacturing: For management of supply chain and for tracking production of items in factories.• Human Resources: For information about employees, salaries, payroll taxes.• Web based services: For taking web users feedback, responses, resource sharing etc.
Advantages Of DBMS• It represents complex relationships among different data items.• Keeps a tight control on data redundancy.• Maintains data dictionary for the storage of information pertaining to data fields and data manipulation.• Ensures that data can be shared across all applications.• Has an automatic intelligent backup and recovery procedure of data.
Disadvantages Of DBMS• Database systems are complex, difficult, and time-consuming to design.• Substantial hardware and software start-up costs.• Damage to database affects virtually all applications programs.• Extensive conversion costs in moving form a file-based system to a database system.• Initial training required for all programmers and users.