Introduction To Databases and DBMS

  • Databases are globally used - air/railway reservation, online auction/shopping etc.
  • Databases are backbone of information age
  • Bigger & better applications are being developed to access and manipulate the stored data
  • To bring down associated costs, following features are desired:
  • support for multiple platforms and specific optimization in a Data Base Management Systems (DBMS)
  • flexible & scalable data sources
  • Database is collection of related data organized and classified in a structured format that is described by metadata (data about data) which defines how data is defined and stored
  • this is required to provide efficient access and maintenance
  • e.g. structuring information in a phonebook - data field, their types, constraints
  • Database is collection of related files of different record types.
  • Yet another definition is: Repository of stored data which is both integrated (I.e. unified with reduced redundancies) and shared. 
  • Data Base Management System (DBMS) record and maintain information (meaningful data).
  • DBMS hides all details of data stored and present to use on desired operation. Some operations include add, modify, delete, create files and data, sorting, math functions, data integrity etc.