Prof. Sujata Rao Introduction to Computers & MIS Data Base Concepts Lesson 6

ssr/1.0/12808 Data Base Concepts 2/ Topics to cover 1.Advantages of Automated System 2.Conceptualizing Data File 3.Evolution of Database System 4.Elements Of Database System 5.DBMS & RDBMS 6.Data Models 7.Factors Determining Database Performance

ssr/1.0/12808 Data Base Concepts 3/ 1. Advantages of Automated System Cycle Time for Information retrieval can be reduced Cycle Time for Information retrieval can be reduced Information can be stored for long period without deterioration Information can be stored for long period without deterioration Data can be updated with small workforce Data can be updated with small workforce Centralised Storing of voluminous data is possible Centralised Storing of voluminous data is possible Data redundancy can be minimised Data redundancy can be minimised Person independent systems possible Person independent systems possible

ssr/1.0/12808 Data Base Concepts 4/ Essentials of Computer Based Information System (CBIS) Ability to store & retrieve information Ability to store & retrieve information Unique file name Unique file name Extension name to depict the file type Extension name to depict the file type Program files - set of instructions Program files - set of instructions

ssr/1.0/12808 Data Base Concepts 5/ 2. Conceptualizing Data File Item_Detail Records or Tuples Fields or Attributes Table or Data File

ssr/1.0/12808 Data Base Concepts 6/ Item_Detail Supplier_Detail Customer_Detail Sales Data Base Tables

ssr/1.0/12808 Data Base Concepts 7/ Components of Database Field/Attributes Field/Attributes Meaningful transaction details. No. of fields is known as the degree of the Table Meaningful transaction details. No. of fields is known as the degree of the Table Records /Tuples Records /Tuples The rows of a table describing the details of a transaction. No. of rows determines the cardinality of a table The rows of a table describing the details of a transaction. No. of rows determines the cardinality of a table Tables Tables Collection of relevant records Collection of relevant records Database Database Collection of related Tables Collection of related Tables

ssr/1.0/12808 Data Base Concepts 8/ Data Base Management System Collection of interrelated Data Collection of interrelated Data Set of programs to control Set of programs to control the organization the organization Storage & retrieval Storage & retrieval

ssr/1.0/12808 Data Base Concepts 9/ Features Add, Modify, Delete, Extract data from a database Add, Modify, Delete, Extract data from a database Provide an environment which is convenient & efficient to use Provide an environment which is convenient & efficient to use A system which provides safety of the data stored from unauthorized use and in event of system crashing. A system which provides safety of the data stored from unauthorized use and in event of system crashing.

ssr/1.0/12808 Data Base Concepts 10/ Elements of Data Base Database Database Tables Tables Queries Queries Forms Forms Reports Reports Macros Macros Modules Modules Relationship Relationship

ssr/1.0/12808 Data Base Concepts 11/ 3. Evolution of Database System Late 1950s & Early 1960s Late 1950s & Early 1960s Flat files organised using sequential method Flat files organised using sequential method Physical & Logical data structures were identical Physical & Logical data structures were identical Data redundancy very high Data redundancy very high 1 st DBMS designed by Bachman in st DBMS designed by Bachman in 1964

ssr/1.0/12808 Data Base Concepts 12/ 3. Evolution of Database System Late 1960s Late 1960s Direct Access & Random Access Files Introduced Direct Access & Random Access Files Introduced Physical data independence became possible Physical data independence became possible 1970s 1970s Database concepts gained popularity Database concepts gained popularity Multiple views from same physical data Multiple views from same physical data Redundancy controlled Redundancy controlled Relational Database Model & Normalization procedures were developed Relational Database Model & Normalization procedures were developed ER Model introduced ER Model introduced Query Language Developed Query Language Developed

ssr/1.0/12808 Data Base Concepts 13/ 3. Evolution of Database System 1980s & 1990s 1980s & 1990s Relational Database introduced -DB2 by IBM Relational Database introduced -DB2 by IBM Microcomputer products developed Microcomputer products developed Client-Server RDBMS gained popularity – ORACLE & SYBASE Client-Server RDBMS gained popularity – ORACLE & SYBASE Object oriented Database Management System introduced Object oriented Database Management System introduced

ssr/1.0/12808 Data Base Concepts 14/ 3. Evolution of Database System Current Trend Current Trend Distributed DBMS, Distributed DBMS, Expert DBMS Expert DBMS Object Oriented DBMS Object Oriented DBMS Extensible DBMS Extensible DBMS

ssr/1.0/12808 Data Base Concepts 15/ 3. Evolution of Database System Late 1950s & Early 1960s Late 1950s & Early 1960s Flat files organised using sequential method Flat files organised using sequential method Physical & Logical data structures were identical Physical & Logical data structures were identical Data redundancy very high Data redundancy very high 1 st DBMS designed by Bachman in st DBMS designed by Bachman in 1964

ssr/1.0/12808 Data Base Concepts 16/ 4. Elements Of Database System

ssr/1.0/12808 Data Base Concepts 17/ 5. DBMS & RDBMS

ssr/1.0/12808 Data Base Concepts 18/ 6. Data Models

ssr/1.0/12808 Data Base Concepts 19/ 7. Factors Determining Database Performance