Chapter 4 Flashcards
How much time DWH should be up
24x7
Does DWH follow traditional life cycle of software system
No
What we use instead of SDLC
CLDS
What is data baisness
Redundancy of data (repetition)
What is histogram/frequency distribution
It gives report on data
At what stage DWH asks for user requirement
At last
Does data in DWH is denormalized
Yes
Why answer comes slow in DWH
Because lot of data
What are the systems in DWH that are concern with performance
OLAP (online analytical processing) execute queries fast within 5 seconds.
How we develop OLAP
Store all possible aggregates
What is data mining
It is sophisticated clustering algorithm. In sophisticated clustering algorithms (e.g. data mining) query can generally be executed in a small number of hours
What is data mart
The data mart is a subset of the data warehouse and is usually oriented to a specific business line. Whereas data warehouses have an enterprise-wide depth, the information in data marts pertains to a single department.
Should data go from ETL to DWH
Yes
What is meta data
It is data about data
Can data mart be independent to DWH or dependent
Both
