xp class agenda – 09/05/2013 answer questions about the course logistics for tutorials and...
TRANSCRIPT
XPXPXPClass 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
3
4
Computer Data Organization Vocabulary
5
Bits
Bytes
Program Files Data 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
7
XPXPXPWhat 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
XPXPXPWhat 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
XPXPXPWhat 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
XPXPXPWhat 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
XPXPXPWhat 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
XPXPXPWhy 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
XPXPXPWhat 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.