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IS 440 Test 2
Terms in this set (61)
refers to how the organization distributes data and database processing physically among the computers in a network.
divides the processing work between 2 or more computers, using a network for connection. It offers flexibility and desirable system redundancy.
a blueprint of how a system will look and how the parts interrelate
the implementation of an architecture
Four Attributes of Distributed Systems
-Where is the processing done?
-How are the processors and other devices interconnected?
-Where is the information stored?
-What rules or standards are used?
Seven Types of Distributed Systems
Decentralized Stand-Alone System
Peer-to-Peer LAN-Based System
Hybrid Enterprisewide System
Advantages of Distributed Systems
Allow data storage out of the way of online, real-time transactions
Allow less expensive media for data storage when all data are not needed all the time by all users
Lower equipment cost because not all system parts need to perform all functions
Lower equipment cost by permitting flexibility in choice of manufacturer
Less expensive than large systems initially because expansion can be planned for without actually purchasing hardware
Disadvantages of Distributed Systems
Difficulty in achieving a reliable system
Security concerns increase commensurately when more individuals have access to the system
Analysts must emphasize the network and the interactions it provides and deemphasize the power of subsystems
Choosing the wrong level of computing to support
is a more specific term that describes the transmitting and receiving of data over communication links between 1 or more computers.
Data Communication over a distance is called
is the sending of information in any form from 1 place to another using electronic or light emitting media
-Electronic Communication Systems
-Electronic Meeting Systems
-Business Processing Systems
Electronic Communication Systems
Electronic Meeting Systems
-decision room conferencing
Business Process Systems
-EDI- Elect Data Inter
-EFT- Elect Funds Transf
- a greater # of competitive vendors, carriers, alliances, and telecommunication network services
- toward interconnected local and global digital networks for voice, data and video with heavy use of high-speed fiber optic lines and satellite channels to form a global information super highway system
- toward the pervasive use of telecommunications networks to support collaborative computing, online business operations, and strategic advantage in local and global markets
Telecommunications basic improvements business process
Better business communication
Better distribution of data
- protocols are concerned with the physical medium, such as wires, radio waves, and optical fibers
Data Link Layer
- takes a raw stream of bits and organizes it into frames by adding special header and trailer bits to indicate the boundaries of each frame.
- the computer interacts with the network to specify the destination address and to request network facilities and priorities.
- provides a transparent transport of data from one computer to another, free of error or duplication.
- provides the mechanism for controlling the dialogue between the communicating systems.
- defines the format of the communicated data.
- contains management functions and useful mechanisms to support distributed applications such as file transfer, electronic mail, and node access to remote computers.
Types of Data Communication
Parallel transmission - each byte is transmitted in its entirety
Serial transmission - data are transmitted one bit at a time through a single line.
3 Modes of communication between devices
- group of interrelated files
- group of related records
- group of related fields
- 1 or more characters
- basic element
Database Analysis Life Cycle
Implementation and loading
Testing and evaluation
Maintenance and evolution
- the designer creates a written specification in words for the Database system to be built.
- conceptual, logical, and physical design steps
Implementation and loading
- once a DBMS has been installed, the database itself must be created within the DBMS.
Testing and evaluation
- the database, once implemented, must be tested against the specification supplied by the client.
- this step is where the system is actually in real usage by the company.
Maintenance and evolution
- time used to fix problems with the system or recommend enhancements or new requirements.
3 Level Database Model
Level 1 - external, conceptual, or local level (user views)
Level 2 - logical or "enterprise data" level
Level 3 - physical or storage level
Database Administrator (DBA)
- a person with responsibilities to focus on the overall performance and integrity of a single DBMS on one or more databases.
- a person whose responsibility is to ensure the integrity of the data resource.
4 Data Models
Hierarchical Model - data are organized into a tree-like structure. The structure allows repeating information using parent/child relationships: each parent can have many children, but each child only has one parent.
Network Model - is a database model conceived as a flexible way of representing objects and their relationships. The network model allows each record to have multiple parent and child records.
Relational Model - a database model that provided for logical connections among files (known as tables) by identifying data from one table in another table.
Object Model - a data model derived from object-oriented programming that encapsulates data and methods, and organizes objects into object classes, among which there can be a hierarchical relationship.
- is the main repository of an organization's historical data, its corporate memory. It contains the raw material to support business intelligence and management decision making.
Major benefits of a data warehouse:
-The ability to reach data quickly since they are located in one place.
-The ability to reach data easily and frequently by end users with web browsers.
Characteristics of a Data Warehouse
Organization - data are organized by subject and contains information relevant for decision support only
Consistency - data in different operational databases may be encoded differently.
Time variant - the data are kept for many years so they can be used for trends, forecasting, and comparisons over time.
Non-volatile - once entered into the warehouse, data are not updated
Relational - typically the data warehouse uses a relational structure.
Client/server - the data warehouse uses the client/server architecture mainly to provide the end user easy access to its data.
Web based - today's data warehouses are designed to provide an efficient computing environment for web based applications.
Concepts in Data Warehousing
Metadata - defining the data
Quality data - once the metadata definitions have been established, the biggest challenge is cleansing the data to adhere to those standards
Data marts - is a small warehouse designed for a strategic business unit or department
-Replicated data mart - one can replicate some subsets of the data warehouse in smaller data marts
-Stand alone data mart - independent data marts without having a data warehouse
Entity-Relationship Diagram (ERD)
Normalization - the transformation of complex user views and data stores to a set of smaller, stable data structures.
First Normal Form 1NF - separate all repeating groups and identify the primary key
Second Normal Form 2NF - ensure all non-key attributes are fully dependent on the primary key
Third Normal Form 3NF - remove dependencies that show non-key attributes being dependent on other non-key attributes
How to solve operational problems:
1. Buy more equipment
2. Fight Fires
3. Document what you are doing
How do you measure operation?
External measures - what customers see system and network uptime response time
turnaround time program failure
Internal measures -what IS people see
% of capacity of computer usage disk storage utilization # of jobs run/rerun
age of applications # of unresolved problems
1. could reduce cost
2. reduces cost of fluctuation
3. makes cost/service tradeoffs
4. allows more rapid or timely development
5. consolidates operations
6. frees management to focus on business
7. offers improved reliability and stability
8. provides opportunity to learn from the contractor
1. could increase cost
2. locks company into a provider
3. reduces control
4. removes knowledge of process from the company
5. decreases ability to use IT strategically
Outsourcing Disadvantages Con't.
Shirking - occurs when a vendor deliberately underperforms, while
claiming full payment
Poaching - occurs when a vendor develops a strategic application for a client and then uses it for other clients
Opportunistic repricing - occurs when a client enters into a long-term contract
with a vendor and the vendor changes financial terms at some point or over charges for unanticipated enhancements and contract extensions
Strategies for Outsourcing
1. Understand the project
2. Divide and conquer
3. Align incentives
4. Write short-period contracts
5. Control subcontracting
6. Do selective outsourcing
Types of Attacks or Misuse
* Ways in which orgs easily compromise their security
* Faulty Operational Practices
* Acceptable user policy/code of ethics
5 Pillars make up today's security techniques
Site Security/System Security/File Security Security Technologies Used
Disaster Recovery Plans
Computer Aided Software Engineering
1. an information repository - business logic, business rules, source code, and
project management data.
2. Front-end tools
3. Back-end tools
4. Development workstation
1. Establish the ground rules - industry standards
2. Foster discipline, planning, documentation, and management
3. Obtain the document, "Final" user requirements
4. Obtain tenders from all appropriate potential vendors
5. Include suppliers in decision making
6. Convert existing data
7. Follow through after implementation