Why is it important for Isle to have an EDW?
Today, reports using up-to-the minute date on specific customers are available the same day enabling the company to react much more quickly to a wide range of customer needs, versus before an EDW, reports would take a week or more to produce making it dif
What is a data warehouse?
DW is a pool of data produced to support decision making; it is also a repository of current and historical data of potential interest to managers throughout the organization
(pg. 40)
Explain the importance of metadata.
Metadata describes the structure of and some meaning about data, thereby contributing to their effective or ineffective use.
The primary purpose of metadata should be to provide context to the reported data; it provides enriching information that leads to
Describe the data warehousing process.
Data imported from various external and internal resources and are cleansed and organized in a manner consistent with the organizations needs
After the data are populated in the data warehouse data marts can be loaded for a specific area or department
Alt
Describe the major components of a data warehouse.
Data source - Data are sourced from multiple independent operational "legacy" systems possibly from external data providers. Data may also come from an OLTP or ERP system. Web data in the form of Web logs may also fee a data warehouse
- Data extraction an
Identify and discuss the role of middleware tools.
search, especially with Web tools.
Middleware tools - Middleware tools enable access to the data warehouse. Power users such as analysts may write their own SQL queries. Others may employ a managed query environment to access data. There are many front-en
What issues should be considered when deciding which architecture to use in developing a data warehouse? List the 10 most important factors.
Issues to be considered:
- Which DBMS should be used
- Will parallel processing and/or partitioning be used
- Will data migration tools be used to load the data warehouse
- What tools will be used to support data retrieval and analysis
10 important factor
Describe data integration.
Data integration comprises three major processes that when correctly implemented, permit data to be accessed and made accessible to an array of ETL and analysis tools and the data warehousing environment: data access, data federation, and change capture.
Describe the three steps of the ETL process.
Your Answer:
ETL - Extraction, transformation, and loading
Extraction - the process of migrating data to a warehouse involves the extraction of data from all relevant sources
Transformation - converting the extracted data into the data warehouse. A transf
Why is the ETL process so important for data warehousing efforts?
When data are managed correctly as an enterprise asset, ETL efforts are significantly reduced, and redundant data are completely eliminated. This leads to huge savings in maintenance and greater efficiency in new development while also improving data qual
List the benefits of data warehouses.
- End users can perform extensive analysis in numberous ways
- A consolidated view of corporate data is possible
- Better and more timely information is possible, A data warehouse permits information processing to be relieved from costly operational syste
What is OLAP and how does it differ from OLTP?
OLAP supports decision making and provides answers to business and management queries.
Data Source:
OLAP - Data warehouse or data mart
OLTP - Transaction database
Reporting:
OLAP - Ad hoc, multidimensional, broadly focused reports and queries
OLTP - Routi
What is a cube? What do drill down, roll up, and slice and dice mean?
A cube in OLAP is a multidimensional data structure that allows fast analysis of data
Drill down - is a specific OLAP technique whereby the user navigates among levels of data ranging from the most summarized to the most detailed
Roll up - involves comput
What are ROLAP, MOLAP, and HOLAP? How do they differ from OLAP?
ROLAP - Relational Online Analytical Processing - accesses the data in a relational database and generates the SQL queries to calculate information at the appropriate level when n end user requests it. With ROLAP, it is impossible to create additional dat
When developing a successful data warehouse, what are the most important risks and issues to consider and potentially avoid?
- Starting with the wrong sponsorship chain
- Setting expectations that you cannot meet
- Engaging in politically na�ve behavior
- Loading the warehouse with information just because it is available
- Believing that data warehousing database design is the
What is scalability? How does it apply to DW?
Good scalability means that queries and other data-access functions will grow linearly with the size of the warehouse
A data warehouse needs to support scalability . The main issues pertaining to scalability are the amount of data in the warehouse, how qu
What is an RDW?
Real-time data warehousing (RDW) - is the process of loading and proving data via the data warehouse as they become available
(pg. 77)
List the benefits of an RDW.
- supplement and expand traditional data warehouse funtions into the realm of tactical decision making
- people are empowered with the information-based decision making at their fingertips
- provides information directly to the customers and suppliers
-th
List some of the drivers for RDW.
- businesses cannot wait a whole day for data
- data warehouses have captured snapshots of an organization's fixed states instead of incremental real-time data showing every state change and almost analogous patterns over time.
- keeping metadata in sync
What steps can an organization take to ensure the security and confidentiality of customer data in its data warehouse?
- Establish effective corporate and security policies and procedure
- Implementing logical security procedures and techniques to restrict access
- Limiting physical access to the data center environment
- Establishing an effective internal control review
What skills should a DWA possess? Why?
A Data warehouse administrator should be familiar with high-performance software, hardware, and networking technologies.
- He or she should also posses solid business insight
-- DWA should be familiar with the decision-making processes so as to suitably d