Database Systems, Data Centers, and Business Intelligence PDF

Chapter 3 Database Systems, Data Centers, and Business Intelligence  Why Learn About Database Systems, Data Centers, and Business Intelligence? Database: – Organized collection of data Database management system (DBMS): – Group of programs that manipulate the database –...

Chapter 3 Database Systems, Data Centers, and Business Intelligence  Why Learn About Database Systems, Data Centers, and Business Intelligence? Database: – Organized collection of data Database management system (DBMS): – Group of programs that manipulate the database – Provide an interface between the database and its users and other application programs Database administrator (DBA): – Skilled IS professional who directs all activities related to an organization’s database  Data Management Without data and the ability to process the data: – An organization could not successfully complete most business activities Data consists of raw facts To transform data into useful information: – It must first be organized in a meaningful way  The Hierarchy of Data Bit (a binary digit): – Circuit that is either on or off Byte: – Typically made up of eight bits Character: – Basic building block of information Field: – Name, number, or combination of characters that describes an aspect of a business object or activity  The Hierarchy of Data (continued) Record: – Collection of related data fields File: – Collection of related records Database: – Collection of integrated and related files Hierarchy of data: – Bits, characters, fields, records, files, and databases  Data Entities, Attributes, and Keys Entity: – General class of people, places, or things (objects) for which data is collected, stored, and maintained Attribute: – Characteristic of an entity Data item: – Specific value of an attribute Data Entities, Attributes, and Keys (continued)  Data Entities, Attributes, and Keys (continued) Key: – Field or set of fields in a record that is used to identify the record Primary key: – Field or set of fields that uniquely identifies the record  The Database Approach Traditional approach to data management: – Each distinct operational system used data files dedicated to that system Database approach to data management: – Pool of related data is shared by multiple application programs The Database Approach (continued) The Database Approach (continued)  Data Modeling and Database Characteristics When building a database, an organization must consider: – Content: What data should be collected and at what cost? – Access: What data should be provided to which users and when? – Logical structure: How should data be arranged so that it makes sense to a given user? – Physical organization: Where should data be physically located?  Data Center Climate-controlled building or set of buildings that: – Houses database servers and the systems that deliver mission-critical information and services Traditional data centers: – Consist of warehouses filled with row upon row of server racks and powerful cooling systems  Data Modeling Building a database requires two types of designs: – Logical design: Abstract model of how data should be structured and arranged to meet an organization’s information needs – Physical design: Starts from the logical database design and fine-tunes it for performance and cost considerations Planned data redundancy: – Done to improve system performance so that user reports or queries can be created more quickly  Data Modeling (continued) Data model: – Diagram of data entities and their relationships Enterprise data modeling: – Starts by investigating the general data and information needs of the organization at the strategic level Entity-relationship (ER) diagrams: – Data models that use basic graphical symbols to show the organization of and relationships between data  The Relational Database Model Relational model: – Describes data using a standard tabular format – Each row of a table represents a data entity (record) – Columns of the table represent attributes (fields) – Domain: Allowable values for data attributes  The Relational Database Model (continued) Manipulating data: – Selecting: Eliminates rows according to certain criteria – Projecting: Eliminates columns in a table – Joining: Combines two or more tables – Linking: Manipulating two or more tables that share at least one common data attribute The Relational Database Model (continued) The Relational Database Model (continued)  Database Management Systems Creating and implementing the right database system: – Ensures that the database will support both business activities and goals Capabilities and types of database systems vary considerably  Overview of Database Types Flat file: – Simple database program whose records have no relationship to one another Single user: – Only one person can use the database at a time – Examples: Access, FileMaker Pro, and InfoPath Multiple users: – Allow dozens or hundreds of people to access the same database system at the same time – Examples: Oracle, Sybase, and IBM  Providing a User View Schema: – Used to describe the entire database – Can be part of the database or a separate schema file DBMS: – Can reference a schema to find where to access the requested data in relation to another piece of data  Creating and Modifying the Database Data definition language (DDL): – Collection of instructions and commands used to define and describe data and relationships in a specific database – Allows database’s creator to describe data and relationships that are to be contained in the schema Data dictionary: – Detailed description of all the data used in the database Creating and Modifying the Database (continued) Creating and Modifying the Database (continued)  Storing and Retrieving Data When an application program needs data: – It requests the data through the DBMS Concurrency control: – Method of dealing with a situation in which two or more users or applications need to access the same record at the same time Storing and Retrieving Data (continued)  Manipulating Data and Generating Reports Data manipulation language (DML): – Commands that manipulate the data in a database Structured Query Language (SQL): – Adopted by the American National Standards Institute (ANSI) as the standard query language for relational databases Once a database has been set up and loaded with data: – It can produce reports, documents, and other outputs  Database Administration DBA: – Works with users to decide the content of the database – Works with programmers as they build applications to ensure that their programs comply with database management system standards and conventions Data administrator: – Responsible for defining and implementing consistent principles for a variety of data issues  Popular Database Management Systems Popular DBMSs for end users: – Microsoft’s Access and FileMaker Pro Database as a Service (DaaS): – Emerging database system – Database administration is provided by the service provider – The database is stored on a service provider’s servers and accessed by the client over a network  Selecting a Database Management System Important characteristics of databases to consider: – Database size – Database cost – Concurrent users – Performance – Integration – Vendor Using Databases with Other Software DBMSs can act as front-end or back-end applications: – Front-end applications interact directly with people – Back-end applications interact with other programs or applications  Database Applications Today’s database applications manipulate the content of a database to produce useful information Common manipulations: – Searching, filtering, synthesizing, and assimilating data contained in a database using a number of database applications  Data Warehouses, Data Marts, and Data Mining Data warehouse: – Database that holds business information from many sources in the enterprise Data mart: – Subset of a data warehouse Data mining: – Information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse  Business Intelligence Involves gathering enough of the right information: – In a timely manner and usable form and analyzing it to have a positive impact on business strategy, tactics, or operations Competitive intelligence: – Limited to information about competitors and the ways that knowledge affects strategy, tactics, and operations  Business Intelligence (continued) Counterintelligence: – Steps organization takes to protect information sought by “hostile” intelligence gatherers Data loss prevention (DLP): – Refers to systems designed to lock down data within an organization – Powerful tool for counterintelligence – A necessity in complying with government regulations that require companies to safeguard private customer data  Distributed Databases Distributed database: – Database in which the data may be spread across several smaller databases connected via telecommunications devices – Gives corporations more flexibility in how databases are organized and used Replicated database: – Holds a duplicate set of frequently used data Distributed Databases (continued)  Online Analytical Processing (OLAP) Software that allows users to explore data from a number of different perspectives Provides top-down, query-driven data analysis Requires repetitive testing of user-originated theories Requires a great deal of human ingenuity and interaction with the database to find information Online Analytical Processing (OLAP) (continued)  Visual, Audio, and Other Database Systems Visual databases: – Can be stored in some object-relational databases or special-purpose database systems Virtual database systems: – Allow different databases to work together as a unified database system Spatial data technology: – Using database to store and access data according to the locations it describes  Summary Data: – One of the most valuable resources that a firm possesses Entity: – Generalized class of objects for which data is collected, stored, and maintained Traditional file-oriented applications: – Often characterized by program-data dependence Relational model: – Places data in two-dimensional tables  Summary (continued) DBMS: – Group of programs used as an interface between a database and its users and other application programs – Basic functions: Providing user views Creating and modifying the database Storing and retrieving data Manipulating data and generating reports  Summary (continued) Data warehouses: – Relational database management systems specifically designed to support management decision making Data mining: – Automated discovery of patterns and relationships in a data warehouse Business intelligence: – Process of getting enough of the right information in a timely manner and usable form