XP Class Agenda – 09/05/2013 Answer questions about the course logistics for tutorials and assignments. Reminder about team declaration. Present concepts of computer data organization. Discuss the different levels of software available to manage data on a computer. Explore the functions of a DBMS vs. an operating system to manage data. Discuss the relative data management capabilities of a DBMS vs. a spreadsheet. 1

Views of Computer Data Organization & Access Conceptual I want to buy music on iTunes. I want to see if that shirt is available in blue in a size medium. Physical 2 Primary Storage/Main Memory Processor ALU Secondary Storage/Disk Data and Programs

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Computer Data Organization Vocabulary 5 Bits Bytes Program FilesData Files Database Fields Records Windows Library: View Folders

6 How does it work? Primary Storage/Main Memory Processor ALU Secondary Storage/Disk Data and Programs when they are not being processed Data and Programs when they are being processed

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XP What is an operating system? Examples: – Windows – Unix – Mac OS X – IBM z/OS, z/VM, UTS – Unisys OS2200 Definition: Set of software that manages a computer’s operations. 8

XP What does an operating system do? Manage hardware and software resources: – Allocate main memory. – Direct processor activities. – Track all program activities. – Manage network connections. – Allocate secondary storage. – Move data and programs from secondary storage to main memory and back again. Manage users (a little…). 9

10 Moving data between primary and secondary storage Secondary Storage/Disk Primary storage/main memory Operating System MS Excel Firefox Neverwinter MS Word

XP What is a DBMS? A set of software that facilitates storage and access of data on a computer. Designed to work with a specific operating system. Examples from vendors. – Microsoft products: Access, FoxPro, SQL Server – Oracle products: Oracle, MySQL – SAP: Sybase, HANA – IBM products: Informix, DB2 – Open-ish: PostgreSQL 11

XP What does a DBMS do? Data structure maintenance: add, delete, change data objects. Data maintenance: add, delete, change data. Data backup and recovery. Concurrency control. Data access (query) optimization. Security. Distributed data management. 12

XP What does MS Access do? Data structure maintenance: add, delete, change tables for data storage. Data maintenance: add, delete, change data in tables. Provide user-friendly tools for data access. – Forms. – Reports. – Integration with other software such as Excel. 13

XP Why do we store data in a database? To protect the “integrity” of the data. To make data more accessible. To make an application more adaptable. 14

XP What other software is available for data storage? Word processing Spreadsheets Application programs – Examples: TurboTax, QuickBooks – Data storage: files, or enhanced file structures – Some application programs rely on a DBMS 15

16 Decision Issue Spreadsheet (Excel) Database (Access) Ability to maintain accurate data Limited. Completely dependent on user for accurate input. Excellent. Many filters/constraints available to protect data accuracy. Ease of showing data in different formats Limited. Can make small color changes to basic spreadsheet. Excellent. Very flexible. Data entered once can be viewed in many different formats. Ease of doing calculations Excellent. Statistics, financial functions available. Limited. Can do calculations, but only basic math. Difficulty of learning/using product Excellent. Easy to learn.Difficult to learn. Necessity for pre- planning Not much planning required. Must plan/design the database in advance.