What does level of Granularity of a fact table signify ?
In simple terms, level of granularity defines the extent of detail. As an example, let us look at geographical level of granularity. We may analyze data at the levels... Read more »
‘Data WareHousing Interview Questions’ - KyaPoocha.com
What is a Data Warehousing?
Datawarehosing is a process of creating,queriring and populating datawarehouse. it includes a number of discrete technologies like Identifying sources Process of... Read more »
Explain the advanatages of RAID 1, 1/0, and 5. What type of RAID setup would you put your TX logs ?
Raid 0 - Make several physical hard drives look like one hard drive. No redundancy but very fast. May use for temporary spaces where loss of the files will not result... Read more »
What type of Indexing mechanism do we need to use for a typical datawarehouse ?
On the fact table it is best to use bitmap indexes. Dimension tables can use bitmap and/or the other types of clustered/non-clustered, unique/non-unique indexes.... Read more »
What is a general purpose scheduling tool ?
A sheduling tool is a tool which is used to shedule the datawarehouse jobs… All the jobs which does some process are sheduled using this tool, which eliminates... Read more »
What is a lookup table ?
A lookup table is nothing but a ‘lookup’ it give values to referenced table (it is a reference), it is used at the run time, it saves joins and space... Read more »
What is real time data-warehousing ?
Real-time data warehousing is a combination of two things: 1) real-time activity and 2) data warehousing. Real-time activity is activity that is happening right... Read more »
What is VLDB ?
It is sometimes used to describe databases occupying magnetic storage in the terabyte range and containing billions of table rows. Typically, these are decision... Read more »
What is Dimensional Modelling?
Dimensional Modelling is a design concept used by many data warehouse desginers to build thier datawarehouse. In this design model all the data is stored in two... Read more »
What are the methodologies of Data Warehousing ?
Every company has methodology of their own. But to name a few SDLC Methodology, AIM methodology are stardadly used. Other methodologies are AMM, World class methodology... Read more »
What is conformed fact?
Conformed dimensions are those table that have a fixed structure. there will b no need to change the metadata of these tables and they can go along with any number... Read more »
What is Difference between E-R Modeling and Dimentional Modeling ?
Basic diff is E-R modeling will have logical and physical model. Dimensional model will have only physical model. E-R modeling is used for normalizing the OLTP database... Read more »
Why fact table is in normal form?
I somewhat disagree venkat. There can just be SKs within a Star schema, which itself is de-Normalized. Now, if there are then FKs on the dimensions as well, I... Read more »
What is the definition of normalized and denormalized view and what are the differences between them ?
I would like to add one more pt. here, as OLTP is in Normalized form, more no. of tables are scanned or referred for a single query, as through primary key and foreign... Read more »
What is junk dimension? What is the difference between junk dimension and degenerated dimension?
A junk dimension is a collection of random transcational codes, flags and text attributes that are unrelated to any particular dimension.The junk dimension is simply... Read more »