INFS 360 Quiz 2

Extract data files end in what?

"tde"

Tableau workbook data files end in what

"twb"

Operational and Analytical Data Update Differences

- Data in operational systems is regularly updated by the users - the end users of analytical databases are only able to retrieve data and updates of the data by the end users are not allowed

Dimensional modeling distinguishes 2 types of tables:

- Dimensions - Facts

Tableau attributes are...

- Dimensions - Measures

A fact table contains

- Foreign keys connecting the fact table to the dimension tables - The measures related to the subject of analysis

Questions and Queries are best visualized as:

- Line Graphs - Column/bar chart - Pie Chart - Scatter Plot

Operational and analytical Data Redundancy Difference

- Operational data supports day-to-day operations so it is used by all types of employees, customers, and other users for various tactical purposes - Analytical data is used by a more narrow set of users for decision-making purposes

2 of the most typical additional attributes that can appear in the fact table are:

- Transaction identifier - Transaction time

Data warehouse is often designed and implemented to answer 2 fundamental questions:

- Who is buying what? - When and where are they doing so?

Why is data warehousing necessary?

1. Need for integrated, company-wide view of high quality information 2. Separation of operational and analytical systems and data

A calculated field is...

A derived variable based on user defined expression using existing: - measures - dimensions - other calculated fields - parameters

Tableau extract

A file created from a data source - file extension is "tde"

INDEX

A special function because it is a table calculation

Dimension Tables

Contain descriptions of the business, organization, or enterprise to which the subject of analysis belongs

Fact Tables

Contains measures related to the subject of analyziz and the foreign keys

Information Retrieval and Decision Support

DWH is a facility for getting information to answer questions of analytical and strategic nature

What emerged as the new DDS Architecture?

Data Warehouse

Dimensional Modeling

Data design methodology used for designing subject-oriented analytical databases, such as data warehouses and data marts

A typical fact table contains what kind of data?

Dynamic data

In the star schema, the chosen subject of analysis is represented by a...?

Fact Table

T/F Tableau operations change data sources

False - Tableau operations never change data sources

T/F Tableau operations change data sources

False - tableau operations DO NOT change data sources

Is Tableau Desktop a data warehouse?

No!

Is Tableau Desktop a database?

No!

The measures in the fact tables are typically...?

Numeric - intended for mathematical computation and quantitative analysis

What are the 7 different Tableau data types?

Numeric (decimal) Numeric (whole) Date and Time (timestamp) Date String Boolean Geographic

Star Schema

The result of dimensional modeling is a dimensional schema known as a star schema that contains facts and dimensions

T/F - the extract file is different from the tableau workbook file

True

Dimensions

Typically categorical data

Measures

Typically quantitative data

Surrogate Key

have no meaning or purpose except to give each dimension a new column that serves as a primary key within the dimensional model instead of the operational key - simple auto-increment integer values

Operational information (Transactional information)

the information collected and used in support of day-today operational needs - results from individual transactions like an ATM withdrawal or purchase of an airline ticket

Operation and Analytical Time-Representation Difference

-Operation data represents the current state of affairs in the real world -Analytical data can represent both the current situation and snapshots of the past

Tableau Desktop

A standalone data visualization and business intelligence software

Operational databases are...?

Application Oriented

"=" in front of the data type ("=Abc") indicates this a...

Calculated field

Approach Change

Realization that the extract processing method is not sufficient

DWH is Integrated! What does this mean?

In DWH data is completely integrated, even when the underlying sources store data differently

Operational and Analytical Difference in Frequency of Queries

Operational queries are typically issued much more often and by more users than analytical queries

Operational and Analytical Difference in Queried Amounts of Data

Operational queries typically process much smaller amounts of data than analytical queries

Subject-oriented

Refers to the difference in purpose of a traditional database system and a DWH - Tradition database system is developed in order to support a specific business operation -DWH is developed to analyze a specific business subject area

Time-variant

Refers to the fact that a DWH contains slices of data across different periods of time. With these data slices, the user can view reports based on current as well as past data.

Structured repository

Refers to the fact that a DWH is a structured data repository like any other database

Enterprise-wide

Refers to the fact that a DWH provides a company-wide view of the information it contains

Historical

Refers to the fact that a DWH typically contains several years worth of data

Analytical Information

Refers to the information collected and used for decision support of tasks requiring data analysis EX: information showing a pattern of use of ATM machines or sales trends in the airline industry

Analytical databases are...?

Subject Oriented

Operational and Analytical Data Level-Of-Detail Difference

-Operational data is more detailed than analytical data -Analytical data is often summarized and/or detailed

Data Time Horizon Difference between analytical and operational data

-Operational systems have a shorter time horizon of data than analytical systems

Data Warehouse

An enterprise-wide structured repository of subject-oriented, time-variant, historical data used for information retrieval and decision support. The data warehouse stores atomic and summary data

What contributed to the evolution of Decision Support Systems?

Approach Change (realization that extract processing was not sufficient) and Architected Environment (Analytic and operational data are different and need to be separate)

Architected Environment

Recognition that there are fundamentally 2 kinds of data: Operational and Analytical

A typical dimension contains what kind of data?

Static Data

Database Management Systems (DBMS)

Systems for transaction processing used to drive detailed operational decisions

Decision Support Systems (DSS)

Systems that facilitate data processing used to drive management decisions

For every dimension under consideration, 2 questions must be answered:

1. Can the dimension table be useful for the analysis of the chosen subject? 2. Can the dimension table be created based on existing data sources?

Blue Pills

Represent discrete variables, typically dimensions

DWH is Subject Oriented! What does this mean?

Data is organized around major subject areas of an enterprise and is therefore useful for an enterprise-wide understanding of those subjects

Green pills

Represent continuous variables, typically measures