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AIS_E2
Accounting Information Systems
Question | Answer |
---|---|
Database Approach | Data is an organizational resource that is used by and managed for the entire organization, not just the originating department |
Database Management System (DBMS) | Is the interface between the database and the various application programs |
Database system | The database, DBMS, and the application programs that access the database through the DBMS are referred to as the database system |
Database Administrator (DBA) | Is responsible for the database |
Data Warehouse | Contains detail and summarized data for a number of years and is used for analysis instead of transaction processing (it not not unusual for them to contain hundreds of terabytes of data) |
What two databases complement each other? | Data Warehouse and a Processing Database (dataWH provide support for strategic decision making) |
When are Data Warehouse updated? | They are updated periodically instead of real time since they are not used for transaction processing |
What does Transaction Processing Minimize and Maximize? | Transaction Processing Databases minimize redundancy and maximize the efficiency of updating them to reflect the results of current transactions. |
Data Warehouses are purposely...? | redundant to maximize query efficiency |
Business Intelligence | data warehouse used to strategic decision making |
What are the two main techniques used in business intelligence? | Online Analytical processing (OLAP) and data mining |
What is Online Analytical Processing (OLAP)? | using queries to guide the investigation of hypothesized relationships in data |
What is Data Mining? | Using sophisticated statistical analysis, including artificial intelligence techniques (such a neural networks) to discover unhypothesized relationships in data |
What is the most time consuming and expensive steps in creating a data warehouse? | verifying accuracy, called scrubbing the data |
What is Data Integration? | Maters files are combined into large pools of data that many application programs access. (files are logically combined and made accessible to various systems) |
What is Data Sharing? | Data is all in one place making it easily accessible to authorized users to easily browse to research a problem or obtain detailed information underlying a report |
What is minimal data redundancy and data inconsistencies? | eliminates the same data being stored so there is no redundancy of data so therefore there is reduced inconsistencies |
What is data independence? | data and the programs that use them are independent (separate) from each other. When you change one it does not effect the other, this facilitates programming and simplifies data management |
What is cross-functional analysis? | relationships from different parts of the organization can be more easily combined and defined and used in the preparation of management reports |
What is a data dictionary? | Information about the structure of the database (each entity will have one)For each data element stored in the database there is a record in the data dictionary describing it |
What are the two separate views of the database approach? | Logical View and Physical View |
What is the Logical View? | how people conceptually organize and understand the data (ex. a sales manager views all customer information as being stored in a table) You don't need to know where data is stored, schema separates the storage of data from the use of data |
What is the Physical View? | how data is physically arranged (how data is actually arranged in a file) and stored within the computer system. |
What is a schema? | A schema is the logical structure of a database |
What are the three levels of a schema? | External, Internal and conceptual |
External-level Schema? | it is the individual view of parts of the database...referred to as a subchema |
Internal-level Schema? | is a low-level view of the database, describes how the data is stored and accessed; including record layouts, definitions, addresses and indexes |
Conceptual-level Schema? | is the organization wide view of the entire database; list all the data elements and relationships among them. |
Who maintains the data dictionary? | Database management system (DBMS) |
What are the languages of the DBMS? | Data definition language, data manipulation language, and the data query language |
What is the data definition language? | builds the data dictionary; creates the database, describes logical views for each user and specifies records or filed security constraints |
What is the data manipulation language? | changes database content, including data element updates, insertions and deletions |
What is the data query language? | contains powerful, east-to-use commands that enable users to retrieve, sort, order, and display data |
What is a report writer? | simplifies report creation |
What are nonkey attributes? | They must describe a characteristic of the object identified by the primary key |
Define System Analysis | The first stage, consists of initial planning to determine the need for and feasibility of developing a new system (makes preliminary decisions, identifies information needs |
What are the five steps of the database design process? | System analysis, conceptual design, physical design, implementation and conversion, operation and maintenance |
Define Conceptual Design | second stage, includes developing the different schemas for the new system at the conceptual, external and internal levels |
Define Physical Design | third stage, consist of translating the internal-level schema into the actual database structure to be implemented into the new system (this is the stage for new applications to be developed) |
Define Implementation and Conversion | Stage four, includes all activities associated with moving the data from the old system to the new database, testing the new, and training for the new. |
Define Operation and Maintenance | Stage five, use and maintain the new system, monitoring system performance, and user satisfaction to determine what enhancements or modifications to make |
What is data modeling? | is the process of defining the database so it faithfully represents all the aspects of the organization; including the external environment |
In what stages of the database design process is the data modeling occurring? | Stage one and two. System Analysis and Conceptual Desgin |
In what stage of the database design process is the data model used? | Stage three, Physical Design |
What is a E-R Diagram? | Entity-relationship diagram, graphical technique for portraying a database schema; it shows the various entities being modeled and the important relationship among them |
What is an entity? | anything about which the organization wants to collect and store information |
How are entities stored in a relational database? | separate tables would be created to store information on each distinct entity |
In a object-oriented database how are entities treated? | separate classes would be created for each distinct entity |
We refer to E-R diagrams developed with the REA model as REA diagrams | True |
What is rule one of the REA data model? | Each event is linked to at least one resource that it affects |
What is rule two of the REA data model? | each event is linked to at least one other event |
What is rule three of the REA data model? | each event is linked to at least two participating agents |
What type of event is it if it increases the quantity of a resource? | Get Event |
What type of event is it if it decreases the quantity of a resource? | Give Event |
What is a stockflow? | a relationship that affects the quantity of a resource (means inventory is flowing/moving)represents the inflow or outflow of that resource |
What is an economic duality relationship? | It is when a give and get event are linked together |
What are the three steps for developing an REA diagram for a specific transaction cycle? | 1) Identify the events in which the management wants to collect info. on 2) Identify the resources affected by each event and the agents who participated 3) Determine the cardinalities of each relationship |
What is a Cardinality? | shows the relationship between two entities (indicates how many instances of one entity can be linked to each specific instance of another entity) |
What is relationship type based on? | Maximum cardinality |
How many different types of relationships are there? | THREE |
When events occur in sequence what is the minimum cardinality? | The minimum cardinality between the first event and the second event is always zero |
What can the maximums between events be? | One or Many (there is an exception if event two does not require event one to occur it...) |
What is the additional rule for creating an integrated REA diagram? (#4) | 4) Every resource has to be linked to at least one event that increments the resource and to at least one event that decrements the resource |
What is the additional rule for creating an integrated REA diagram? (#5) | 5) If event A can be linked to more than one other event, but the other events can not be linked simultaneously to all of those other events, then the REA diagram should show that event A is linked to a minimum of 0 of each of those other events |
What are the three steps to implementing an REA diagram in a relational database? | 1) create a table (each distinct entity in the diagram and each many-to-many) 2) Assign Attributes to appropriate tables 3)Use foreign keys to implement one-to-one and one-to-many relationships |
When implementing an REA diagram in a relational database how many tables should there be? | 20 tables |
What are concatenated keys? | multiple-attribute primary keys |
What must an attribute be? | must be a fact about the object represented by the primary key |
Where are price and cost stored? | they are stored as attributes in many different tables |
For price and cost data what does the inventory table store? | list-price |
For price and cost data what does the sales-inventory table store? | actual sales price |
How should time independent data be store? | as an attribute of a resource or agent |
How should data that vary across time be stored? | with event entities or with a M:N relationship that involves at least one event |
What does implementing relationships in the database (relational database) mean? | we are talking about what table is going to get the foreign key. |
How do you determine who gets the foreign key? | If we have sequential events the primary key of the event that occurs first is going to be the foreign key in the event that occurs second |
Using foreign keys to implement one-to-many relationships | You place the primary key of the entity that can occur once as the foreign key in the entity that can occur many times |