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Data Warehousing Interview questions

Data Warehousing Interview questions with answers posted on August 07, 2008 at 17:10 pm by Rajmeet Ghai What is Data warehousing? Answer - A data warehouse can be considered as a storage area where interest specific or relevant data........             What are fact tables and dimension tables? Answer - As mentioned, data in a warehouse comes from the transactions. Fact table in a data warehouse consists........ What is ETL process in data warehousing? Answer - ETL is Extract Transform Load. It is a process of fetching......... Explain the difference between data mining and data warehousing. Answer - Data warehousing is merely extracting data from different sources, cleaning the........ What is an OLTP system and OLAP system? Answer - OLTP: Online Transaction and Processing helps and manages applications based........ What are cubes? Answer - A data cube stores data in a summarized version which helps in a faster analysis of data.......... What is snow flake scheme design in database? Answer - A snowflake Schema in its simplest form is an arrangement of fact tables......... What is analysis service? Answer - Analysis service provides a combined view of the data used in OLAP......... Explain sequence clustering algorithm. Answer - Sequence clustering algorithm collects similar or related paths, sequences of data......... Explain discrete and continuous data in data mining. Answer - Discreet data can be considered as defined or finite data.......... Explain time series algorithm in data mining. Answer - Time series algorithm can be used to predict continuous values of data....... What is XMLA? Answer - XMLA is XML for Analysis which can be considered as a standard for accessing data in OLAP....... Explain the difference between Data warehousing and Business Intelligence. Answer - Data Warehousing helps you store the data while business intelligence..... What is Dimensional Modeling? Answer - Dimensional modeling is often used in Data warehousing....... What is surrogate key? Explain it with an example. Answer - Data warehouses commonly use a surrogate key....... What is the purpose of Factless Fact Table? Answer - Fact less tables are so called because they simply contain........ What is a level of Granularity of a fact table? Answer - A fact table is usually designed at a low level of Granularity........... Explain the difference between star and snowflake schemas. Answer - A snow flake schema design is usually more complex than a start schema..... What is the difference between view and materialized view? Answer - A view is created by combining data from different tables........ What is a Cube and Linked Cube with reference to data warehouse? Answer - A data cube stores data in a summarized version which helps in a faster analysis............ What is junk dimension? Answer - In scenarios where certain data may not be appropriate to store in.... What are fundamental stages of Data Warehousing? Answer - Stages of a data warehouse helps to find and understand.......

Click here to share knowledge by answering these questions What is Data Warehousing?  What is Virtual Data Warehousing? Explain in brief various fundamental stages of Data Warehousing. What is active data warehousing? List down differences between dependent data warehouse and independent data warehouse. What is data modeling and data mining? What is this used for? Difference between ER Modeling and Dimensional Modeling. What is the difference between data warehousing and business intelligence? Describe dimensional Modeling. What is snapshot with reference to data warehouse? List out types of dimension tables. What is degenerate dimension table? What is Data Mart? Define Fact table. Define Dimension table. What is the difference between metadata and data dictionary? What is ETL? Describe the various methods of loading Dimension tables. What is OLTP? What is the difference between OLAP and data warehouse? What is ODS? What is OLAP? List out the difference between OLTP and OLAP. Describe the foreign key columns in fact table and dimension table. Explain in brief Data Mining. Difference between view and materialized view. Explain in brief ER Diagram. What is VLDB? What is cube grouping? Define the term slowly changing dimensions (SCD). Differences between star and snowflake schema. What is a Star Schema? Why fact table is in normal form despite the fact that de-normalized is improves data warehouse processes? Explain the use lookup tables and Aggregate tables. What is a Cube and Linked Cube with reference to data warehouse? What is real time data-warehousing? What is conformed dimensions use for? What is conformed fact? What Snow Flake Schema? How do you load the time dimension? What is junk dimension? What is a level of Granularity of a fact table? Define non-additive facts. Explain the use of factless facts table. What is hybrid slowly changing dimension? Define BUS Schema. List out difference between SAS tool and other tools. Why is SAS so popular? What is data cleaning? How can we do that? Explain in brief critical column. What is data cube technology used for? Click here to share knowledge by answering these questions