![Network ModelNetwork Model
Early 1960s, Charles Bachmann developed first DBMS at Honeywell, Integrated Data
Store (IDS).
Network data model identified the following three database components:
•Network schema—database organization[structure]
•Sub-schema—view s of database per user
•Data management language — at low level , procedural
•Later 1971 standardized by the CODASYL (Conference on Data Systems Language)](https://image.slidesharecdn.com/databasesystemsintroduction-180826060405/85/Database-systems-introduction-26-320.jpg)
Database systems introduction
- 1. Database SystemsDatabase Systems Delivered By: Mr. karthibanDelivered By: Mr. karthiban MSc in PM, BSc (Hons) in Computing , MBCS, BTEC HND in CSD
- 2. Data vs. InformationData vs. Information • Data • Raw facts; building blocks of information • Unprocessed information. • Information: • Data processed to reveal meaning Accurate, relevant, and timely information is key to good decision making. Good decision making is the key to survival in a global environment.
- 3. Database (DB)Database (DB) • A database is a collection of information that is organized so that it can be easily accessed, managed and updated. • Data is organized into rows, columns and tables, and it is indexed to make it easier to find relevant information. • Data gets updated, expanded and deleted as new information is added. • Databases process workloads to create and update themselves, querying the data they contain and running applications against it.
- 4. Database Management SystemDatabase Management System • A Database Management System (DBMS) is a computer software application that interacts with the user, other applications, and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases
- 5. Advantage of DBMSAdvantage of DBMS Improved data sharing. Improved data security. Better data integration. Minimized data inconsistency. Improved data access. Improved decision making. Increased end-user productivity.
- 6. Disadvantage of DBMSDisadvantage of DBMS • Increased costs • Management complexity • Maintaining currency • Frequent upgrade/replacement cycles
- 7. Types of DatabasesTypes of Databases
- 8. Single-UserSingle-User Supports only one user at a time Single-user database running on a personal computer
- 9. WorkgroupWorkgroup Supports multiple users at the same time Workgroup: Multi-user database that supports a small group of users or a single department Enterprise: Multi-user database that supports a large group of users or an entire organization
- 10. CentralizedCentralized Supports data located at a single site
- 11. DistributedDistributed Supports data distributed across several sites
- 12. Transactional (or production)Transactional (or production) Supports a company’s day-to-day operations
- 13. Data warehouseData warehouse • Stores data used to generate information required to make tactical or strategic decisions • Often used to store historical data • Structure is quite different
- 14. Introduction to MySQLIntroduction to MySQL
- 15. MySQLMySQL • MySQL is a very popular, open source database. • Officially pronounced “my Ess Que Ell” (not my sequel). • Handles very large databases; very fast performance. • Why are we using MySQL? • Free (much cheaper than Oracle!) • Each student can install MySQL locally. • Easy to use Shell for creating tables, querying tables, etc.
- 16. MySQL IntroductionMySQL Introduction • MySQL is a database management system • SQL stands for the Structured Query Language. It defines how to insert, retrieve, modify and delete data • Free from www.mysql.com • Reference sites • NASA, Yahoo!, Compaq, Motorola, Facebook
- 17. DATABASE MODELDATABASE MODEL A database model is a type of data model that determines the logical structure of a database and fundamentally determines in which manner data can be stored, organized, and manipulated.
- 18. The Evolution of DatabaseThe Evolution of Database From pre-stage flat-file system, to relational and object-relational systems, database technology has gone through several generations and its history that is spread over more than 40 years now.
- 19. Flat FilesFlat Files • 1968 File-Based: predecessor of database, Data was maintained in a flat file. • Earlier, punched cards technology was used to store data – later, files. But the files have no as such advantage, rather have several limitations.
- 21. DATABASE MODELSDATABASE MODELS Database management systems are usually categorized according to the data model. Common models include: 1.Hierarchical model 2.Network model 3.Relational model 4.Entity-Relationship model 5.Object model 6.Object-relational model
- 22. Hierarchical ModelHierarchical Model In mid 1960s, Rockwell partnered with IBM - create Information Management System (IMS). IMS lead the mainframe database market in 70’s and early 80’s. Hierarchical data model.
- 23. Hierarchical data modelHierarchical data model • In a Hierarchical model, data is organized into a tree-like structure, implying a single parent for each record. A sort field keeps sibling records in a particular order. • Hierarchical structures were widely used in the early mainframe database management systems, such as the Information Management System (IMS) by IBM, and now describe the structure of XML documents. • This structure allows one one-to-many relationship between two types of data. This structure is very efficient to describe many relationships in the real world; recipes, table of contents, ordering of paragraphs/verses, any nested and sorted information.
- 24. Hierarchical Data ModelHierarchical Data Model
- 25. AdvantagesAdvantages •Less redundant data. •Data independence. •Database security and integrity LimitationsLimitations •Complex implementation •Difficult to manage and lack of standards, can’t easily handle many-many relationships. •Lacks structural independence.
- 26. Network ModelNetwork Model Early 1960s, Charles Bachmann developed first DBMS at Honeywell, Integrated Data Store (IDS). Network data model identified the following three database components: •Network schema—database organization[structure] •Sub-schema—view s of database per user •Data management language — at low level , procedural •Later 1971 standardized by the CODASYL (Conference on Data Systems Language)
- 27. Network ModelNetwork Model The Network model expands upon the hierarchical structure, allowing many-to-many relationships in a tree-like structure that allows multiple parents. It was most popular before being replaced by the relational model, and is defined by the CODASYL specification. The network model organizes data using two fundamental concepts, called records and sets. Records contain fields (which may be organized hierarchically, as in the programming language COBOL). Sets (not to be confused with mathematical sets) define one-to-many relationships between records: one owner, many members. A record may be an owner in any number of sets, and a member in any number of sets.
- 29. AdvantagesAdvantages •Ability to handle more relationship types •Ease of data access •Data Integrity •Data Independence LimitationsLimitations •System complexity and difficult to design and maintain •Lack of structural independence as data access method is navigational.
- 30. Relational ModelRelational Model 1970s, E.F. Codd, an IBM researcher •Disconnected the schema (logical organization) of a database from the physical storage methods. •First successful database product for microcomputers was dBASE •The term Relational Database Management System (RDBMS) was introduced during this period
- 31. Relational ModelRelational Model A database based on the relational model developed by E.F. Codd. A relational database allows the definition of data structures, storage and retrieval operations and integrity constraints. In such a database the data and relations between them are organized in tables. A table is a collection of records and each record in a table contains the same fields. Properties of Relational Tables: Values Are Atomic Each Row is Unique Column Values Are of the Same Kind The Sequence of Columns is Insignificant The Sequence of Rows is Insignificant Each Column Has a Unique Name
- 33. Entity-Relationship (ER) modelEntity-Relationship (ER) model In 1976, Dr. Peter Chen •The entity-relationship model (or ER model) is a way of graphically representing the logical relationships of entities (or objects) in order to create a database.
- 34. Entity-Relationship (ER) modelEntity-Relationship (ER) model
- 35. Object-Oriented ModelObject-Oriented Model 1985 - Object-Oriented model Object oriented databases are also called Object Database Management Systems (ODBMS). Object databases store objects rather than data such as integers, strings or real numbers. Objects are used in object oriented languages such as Smalltalk, C++, Java, and others. Objects basically consist of the following: Attributes - Attributes are data which defines the characteristics of an object. This data may be simple such as integers, strings, and real numbers or it may be a reference to a complex object. Methods - Methods define the behavior of an object and are what was formally called procedures or functions.
- 36. Object-oriented Relational modelObject-oriented Relational model 1990s - Object-oriented Relational model Object-oriented models are very powerful but also quite complex. With the relatively new object-relational database model is the wide spread and simple relational database model extended by some basic object-oriented concepts. These allow us to work with the widely know relational database model but also have some advantages of the object-oriented model without its complexity.
- 37. The database system can be divided intoThe database system can be divided into four components.four components. Users : Users may be of various type such as DB administrator, System developer and End users. Database application : Database application may be Personal, Departmental, Enterprise and Internal. DBMS : Software that allow users to define, create and manages database access, Ex: MySQL, Oracle etc. Database : Collection of logical data.