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…).

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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

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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.