Topic 3- Databases- Chapter 5

• Data governance


  An approach to managing information across an entire organization
• Master data management


  Part of data governance
• Master data


  Core data that is critical to an organization
• Database management systems


  • Minimize data redundancy
  • Minimize data isolation
  • Minimize data inconsistency
  • Maximize data security
  • Maximize data integrity
  • Maximize data independence
• Bit


  Smallest unit of data
• Byte


  Group of bits
• Field


  Smallest unit of data in a database
• Data file or table


  Collection of related fields
• Database


  Collection of related data files or tables
• Database management system


  Software that controls the organization, storage, management, and retrieval of data in a database
• Relational database model


  Data model that represents data in tables with rows and columns
• Data model


  Logical structure of a database
• Entity


  Representation of a person, place, thing, or event
• Instance


  Specific occurrence of an entity
• Attribute


  Characteristic of an entity
• Primary key


  Unique identifier for each instance of an entity
• Secondary key


  Additional attribute used to identify an instance of an entity
• Foreign key


  Attribute in one table that matches the primary key of another table
• Big Data


  Diverse, high-volume, high-velocity information assets that require new forms of processing to enable enhanced decision making, insight discovery, and process optimization
• Characteristics of Big Data

  • Volume
  • Velocity
  • Variety
• Big Data can come from untrusted data sources
• Big Data is dirty
• Big Data changes, especially in data streams
• Data warehouse


  A repository of historical data that are organized by subject to support decision makers in the organization
• Data mart


  A low-cost, scaled-down version of a data warehouse designed for end-user needs in a strategic business unit (SBU) or individual department
• Basic characteristics of data warehouses and data marts

  • Organized by business dimension or subject
  • Use online analytical processing (OLAP)
  • Integrated
  • Time variant
  • Nonvolatile
  • Multidimensional
• Knowledge management (KM)


  A process that helps manipulate important knowledge that comprises part of the organization's memory, usually in an unstructured format
• Knowledge


  Information combined with experience, context, interpretation, and reflection
• Explicit knowledge


  Knowledge that can be easily codified and shared
• Tacit knowledge


  Knowledge that is difficult to codify and share
• Knowledge management systems (KMS)


  The use of modern information technologies to systematize, enhance, and expedite intrafirm and interfirm knowledge management
• The KMS cycle


  1. Create knowledge

  2. Capture knowledge

  3. Refine knowledge

  4. Store knowledge

  5. Manage knowledge

  6. Disseminate knowledge
• Structured Query Language (SQL)


  A query language used to interact with relational databases
• Query By Example (QBE)


  A query language that allows users to specify examples of the data they want to retrieve
• Entity-relationship (ER) diagram


  A graphical representation of the relationships between entities in a database
• Business rules


  Constraints that define the relationships between entities
• Data dictionary


  A repository of information about the data, such as meaning, relationships to other data, origin, usage, and format
• Degree of a relationship


  The number of entities involved in a relationship (unary, binary, ternary)
• Cardinality


  The number of instances of one entity that can be associated with one instance of another entity (one-to-one, one-to-many, many-to-many)
• Normalization


  The process of organizing data in a database to reduce redundancy and improve data integrity