Data base

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What is data and information? What is data base? What is data base management system? What are various data base models??? Components of data base function of data base. Advantages of data base. And what is system language query???
Basic Data Management Concept
Organizing Data in a Database
Database Management Systems

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Data base

  1. 1. g A h H
  2. 2. w Data consist on Raw facts & figures Data is lengthy and uncertain Difficult to regenerate Information is process foam of data and it is certain. Information is short and certain Easy to regenerate
  3. 3. A component of a database which contains a single item such as name, number, or combination of characters that describes some aspect of an object Collection of related fields that describe some object or activity  Collection of related records Collection of integrated and related files or tables
  4. 4. Generalized class of people, places, or things for which data is collected, stored, and maintained Characteristic of an entity For example, employee number or last name The specific value of an attribute is called a data item Field in a record used to identify the record Uniquely identifies the record in a database file A data anomaly such as a two people with the same name can be resolved
  5. 5.          Collection of interrelated data Set of programs to access the data DBMS contains information about a particular enterprise DBMS provides an environment that is both convenient and efficient to use. Banking: all transactions Airlines: reservations, schedules Universities: registration, grades Sales: customers, products, purchases Human resources: employee records, salaries, tax deductions
  6. 6.  A collection of data organized to meet users’ needs  A group of programs that manipulate the database and provide an interface between the database and the user or the database and application programs  Comprised of database, DBMS, and application programs
  7. 7. DBMS Hardware software Data Users Procedures
  8. 8. Store important data such as phone numbers, addresses, text, images, audi o signals Perform routine tasks such as preparing income tax forms or produce paychecks for employees Make better decisions by using information gathered from databases and creating reports Protect data from attacks and unauthorized access
  9. 9. Data dictionary Access & security utilities Report generator Backup & recovery Query language
  10. 10. refers to both the practice and the study of the activities people perform in order to acquire, organize, maintain, retrieve and use information items such as documents (paper-based and digital), web pages and email messages for everyday use to complete tasks (work-related and not) and fulfill a person’s various roles (as parent, employee, friend, member of community, etc.)  Address Book  Email
  11. 11.  PC databases  Centralized database  Client/server databases  Distributed databases  Database models Data information knowledge
  12. 12. Central Computer Client Client Network Database Server Client
  13. 13. Data (the database) Software Hardware Users  We focus mainly on the software Store Update Retrieve Organise Protect their data
  14. 14. Reduced data redundancy Standardization of data access Easier modification and updating Improved data integrity Shared data and information resources
  15. 15. defines the logical design of data.  Describes the relationships between different parts of data. Hierarchical model 3 models  Network model Relational model
  16. 16.       Determines where data are actually stored on the storage device. Low-level access method Defines the logical view of the data The main functions of DBMS are in this level. Interacts directly with the user. Change the data coming from the conceptual level to a format and view that are familiar to the users.
  17. 17. Data are organized as an upside down tree. Each entity has only one parent but can have several children
  18. 18. The entities are organized in a graph.  Some entities can be accessed through several paths 
  19. 19.    Data are organized in two-dimensional tables called relations. The tables are related to each other. The most popular model.
  20. 20. Standardized by ANSI and ISO for use on relational databases.  It is a declarative (not procedural) language, which means that the users declare what they want without having to write a step-by-step procedure.  First implemented by Oracle in 1979.  SQL allows you to combine the following statements to extract more complex information from database. 
  21. 21.      It is not a new model. It is based on relational model. The data are stored on several computers that communicate through the Internet or some private WAN. Data are either fragmented, with each fragment stored at one site, or data are replicated at each site. Fragmented distributed databases Replicated distributed databases
  22. 22. Some application like to see data as a structure such as a record made of fields.  Tries to keep the adv. of the relational model and allows applications to access structured data.  In an OODB, objects and their relations are defined. In addition, each object can have attributes that can be expressed as fields. 

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