Week 1: Introduction to Database

• Database


  an organised collection of logically related data
• Data: stored representations of meaningful objects and events


  Structured: numbers, text, dates

  Unstructured: images, video, documents
• Information

  data processed to increase knowledge in the person using the data
• Metadata

  data that describes the properties and context of user data
• Problems with database is Program-Data Dependence which:

  changing the structure or storage characteristics of data would require changing the applications that accesses it
• Problems with data base Data Redundancywhich:

  unnecessarily storing same data at different places; duplication of information in different files
• Problems with database is Data Inconsistencywhich:

  different and conflicting versions of same data occur at different places
• Problems with database is Data Anomalieswhich:

  abnormalities when all changes in redundant data are not made correctly
• Database Management System (DBMS)

  a collection of programs that manages the database structure and controls access to the data stored in the database examples like oracle, SQL server or MYSQL
• Redundancy increases the risk of inconsistent data. 

  True
• A collection of programs that manages the database structure and controls access to the data stored in the database is called a

  Database Management System
• Advantages of the Database Approach

  Program-data independence, planned data redundancy, Improved data consistency, Improved data sharing, Increased application development productivity, Enforcement of standards, Improved data quality, Improved data accessibility and responsiveness
• whats the first DBMS Function?


  Data dictionary: Store definitions of the data elementsand their relationships
• what's the second DBMS Function?

  Data storage management (Performance tuning: Ensures efficient performance of the database in terms of storage and access speed)
• whats the third DBMS Function


  Data transformation and presentation (Transforms entered data to conform to required data structures)
• whats the fourth DBMS Function


  Security management (Enforces user security and data privacy)
• whats the fifth DBMS Function


  Multiuser access control (Sophisticated algorithms ensure that multiple users can access the database concurrently without compromising its integrity)
• whats the sixth DBMS Function




  Backup and recovery management (Enables recovery of the database after a failure)
• whats the seventh DBMS Function


  Data integrity management (Minimizes redundancy and maximizes consistency)
• whats the eight DBMS Function


  Database access languages and application programming interfaces •Query language: Lets the user specify what

  must be done without having to specify how

  •Structured Query Language (SQL): De facto

  query language and data access standard

  supported by the majority of DBMS vendors
• whats the nineth DBMS Function





  Database communication interfaces (Accept end-user requests via multiple, different network environments)
• DBMS Disadvantages


  Increased costs, Vendor dependence, Frequent upgrade/replacementcycles
• what are the different types of databases


  Data Locations, Data Usage, Analytical database
• Data integrity management is a DBMS function, which


  Minimizes redundancy and maximizes consistency
• Unnecessarily storing the same data in different places is called


  Data redundancy
• Which of the following is NOT an advantage of database systems

  Redundant data
• With the traditional file processing approach, each application or program shares data files, thus enabling much data sharing

  False