Database Management3-1 L3 Database Management Santa R. Susarapu Ph.D. Student Virginia Commonwealth University

Database Management3-2 Objectives Understand why databases are important to modern organizations Understand why databases are important to modern organizations Understand how databases work Understand how databases work Demonstration of Database Creation using Oracle/SQL*Plus Demonstration of Database Creation using Oracle/SQL*Plus Understand how organizations can maximize their strategic potential with databases Understand how organizations can maximize their strategic potential with databases

Database Management3-3 Database Management for Strategic Advantage Use databases to: Use databases to:  Create a book  Track book sales  Set salaries and wages  Pay employees Database – a collection of related attributes about entities and organized in a way to facilitate data searches Database – a collection of related attributes about entities and organized in a way to facilitate data searches  Entity = Table  Record = Column in a Table

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Database Management3-5 Database Management for Strategic Advantage The Database Approach: Foundational Concepts The Database Approach: Foundational Concepts  DBMS is a software to create, store, organize, and retrieve data from a single database or several databases  Example  Microsoft Access  Oracle

Database Management3-6 Database Management for Strategic Advantage Traditional way to deal with electronic data manipulation Traditional way to deal with electronic data manipulation  File Processing Approach  Each department will have a separate database  Decentralized approach  Difficult to modify

Database Management3-7 Database Management for Strategic Advantage Database Approach - Centralized Approach Database Approach - Centralized Approach Advantages Advantages  Program-data independence  Minimal data redundancy  Improved data consistency  Improved data sharing  Increased productivity of application development  Enforcement of standards  Improved data quality  Improved data accessibility  Reduced program maintenance

Database Management3-8 Database Management for Strategic Advantage Database Approach – Disadvantages Database Approach – Disadvantages  Ownership conflict  Backup and recovery issues  Complex management  Specialized personnel & training  Conversion costs

Database Management3-9 Database Management for Strategic Advantage Effective Management of Databases Effective Management of Databases  The database administrator (DBA) :  Works with programmers and analysts to design and implement the database  Works with users and managers to establish database policies  Implements security features and establishes database permissions

Database Management3-10 Key Database Activities Entering Data Entering Data  Online forms  Preprinted forms  Telephone conversations Querying Data – Retrieval technique Querying Data – Retrieval technique  Structured Query Language (SQL)  Query by example (QBE)  Demonstration using MS Access Database

Database Management3-11 Key Database Activities Creating Database Reports Creating Database Reports  Report – a compilation of data that is organized and produced in printed format  Report Generators  Demonstration using MS Access Database

Database Management3-12 Key Database Activities Database Design Database Design  Must be organized  Few or no redundancies  Data model – a map of entity relationships  Keys  Primary key  Combination primary key  Foreign key

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Database Management3-14 Key Database Activities Entity-Relationship Diagramming (ERD) Entity-Relationship Diagramming (ERD)  Commonly used when designing databases  One draws entities (tables) as boxes and lines between entities to show relationships  Example: Mountain Animals ERD  Handout

Database Management3-15 Key Database Activities Database Associations Database Associations  One-to-one relationship  One-to-many relationship  Many-to-many relationship

Database Management3-16 Key Database Activities The Relational Model of Databases The Relational Model of Databases  Entities linked by a common key field  Records = rows  Fields = columns  Other models exist  Hierarchical  Network  Object-oriented model

Database Management3-17 Key Database Activities Normalization Normalization  A technique for making complex databases more efficient and more easily handled by the DBMS  1 st Normal Form (1NF)  2 nd Normal Form (2NF)  3 rd Normal Form (3NF)  Boyce-Codd Normal Form (BCNF)  Eliminates data redundancy and modification anomalies

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Database Management3-20 Key Database Activities Data Dictionary a.k.a. metadata Data Dictionary a.k.a. metadata  A document that explains each piece of information in the database  Field name  Data type Numeric, text, date/timeNumeric, text, date/time Useful for sorting and allocating storageUseful for sorting and allocating storage  Is this field a key field?  Business rules Update authorityUpdate authority Valid data valuesValid data values

Database Management3-21 Creation of Databases using Oracle/SQL*Plus Oracle Enterprise Manager Oracle Enterprise Manager SLQ*Plus SLQ*Plus iSQL*Plus iSQL*Plus

Database Management3-22 How Organizations Get the Most from Their Data Linking Web Sites to Databases Linking Web Sites to Databases  Example: Amazon  2.5 million titles  Managing online data effectively

Database Management3-23 How Organizations Get the Most from Their Data Data Mining Data Mining  A method for better understanding data  Information on customers, products, markets, etc.  Drill down: from summary to more detailed data  Sort and extract information  Trends, correlations, forecasting, statistics

Database Management3-24 How Organizations Get the Most from Their Data Data Mining Data Mining  Online Transaction Processing (OLTP)  Immediate automated responses to user requests  Multiple concurrent transactions  A big part of interactive Internet e-commerce

Database Management3-25 How Organizations Get the Most from Their Data Data Mining Data Mining  Online Analytical Processing (OLAP)  Graphical software tools that provide complex analysis of data stored in a database  Drills down to deeper levels of consolidation  Time series and trend analysis  “What if” and “why” questions

Database Management3-26 How Organizations Get the Most from Their Data Data Mining Data Mining  Merging Transaction and Analytical Processing  Real-time OLAP diminishes performance because the database must be “locked” during execution time  Solution: replicate transactions on a 2 nd database server

Database Management3-27 How Organizations Get the Most from Their Data Data Mining Data Mining  Merging Transaction and Analytical Processing  Operational Systems Interact with customers and run a business in real timeInteract with customers and run a business in real time Examples: Order processing, reservation systemsExamples: Order processing, reservation systems  Informational Systems Support decision making based on stable point-in-time or historical dataSupport decision making based on stable point-in-time or historical data

Database Management3-28 How Organizations Get the Most from Their Data Data Warehousing Data Warehousing  Integrating multiple large databases into a single repository  Queries, analysis, and processing  Purpose: put key business information into the hands of decision makers  Cost: millions

Database Management3-29 How Organizations Get the Most from Their Data Data Marts Data Marts  Instead of one large data warehouse, many organizations create multiple data marts  Each contains a subset of the data  Example: finance, inventory, personnel  Each data mart is customized for particular DSS applications  Cost: typically less than $1 million