Data Warehousing

Data Warehousing Interview questions

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Data Warehousing Interview - 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.......

Data Warehousing Interview - posted on May 11, 2009 at 14:40 pm by Vidya Sagar

What is Virtual Data Warehousing?

The aggregate view of complete data inventory is provided by Virtual Warehousing........

What is active data warehousing?

The transactional data captured and reposited in the Active Data Warehouse......

List down differences between dependent data warehouse and independent data warehouse.

Dependent data ware house are build........

What is data modeling and data mining? What is this used for?

Designing a model for data or database is called data modelling........

Difference between ER Modeling and Dimensional Modeling.

Dimensional modelling is very flexible for the user perspective........

What is snapshot with reference to data warehouse?

A snapshot of data warehouse is a persisted report from the catalogue.........

What is degenerate dimension table?

The dimensions that are persisted in the fact table is called dimension table.........

What is Data Mart?

Data Mart is a data repository which is served to a community of people.......

What is the difference between metadata and data dictionary?

Metadata describes about data. It is ‘data about data’. It has information about how and when......

Describe the various methods of loading Dimension tables.

The following are the methods of loading dimension tables.......

What is the difference between OLAP and data warehouse?

The following are the differences between OLAP and data warehousing......

Describe the foreign key columns in fact table and dimension table.

The primary keys of entity tables are the foreign keys of dimension tables.......

What is cube grouping?

A transformer built set of similar cubes is known as cube grouping. A single level in one dimension......

Define the term slowly changing dimensions (SCD).

Slowly changing dimension target operator is one of the SQL warehousing operators......

What is a Star Schema?

The simplest data warehousing schema is star schema.......

Differences between star and snowflake schema.

Star Schema: A de-normalized technique in which one fact table is associated with several dimension tables.......

At the time of updating the data warehouse, a lookup table is used.......

What is real time data-warehousing?

The combination of real-time activity and data warehousing is called real time warehousing.......

What is conformed fact? What is conformed dimensions use for?

Allowing having same names in different tables is allowed by Conformed facts.......

Define non-additive facts.

The facts that can not be summed up for the dimensions present in the fact table are called non-additive facts.......

Define BUS Schema.

A BUS schema is to identify the common dimensions across business processes......

List out difference between SAS tool and other tools.

The differences between SAS and other tools are......

Why is SAS so popular?

Statistical Analysis System is an integration of various software products which allows the developers to perform.......

What is data cleaning? How can we do that?

Data cleaning is also known as data scrubbing. Data cleaning is a process which ensures the set of data is correct and accurate......

Explain in brief about critical column.

A column (usually granular) is called as critical column which changes the values over a period of time.......

What is data cube technology used for?

Data cube is a multi-dimensional structure. Data cube is a data abstraction to view aggregated data from a number of perspectives........

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Also read SQL Server 2005 Analysis Services Interview Questions What is SQL Server 2005 Analysis Services (SSAS)? What are the new features with SQL Server 2005 Analysis Services (SSAS)? What are SQL Server Analysis Services cubes? Explain the purpose of synchronization feature provided in Analysis Services 2005. Explain the new features of SQL Server 2005 Analysis Services (SSAS). [Hint - Unified Dimensional Model, Data Source View, new aggregation functions and querying tools].................... Business Intelligence interview questions Explain the concepts and capabilities of Business Intelligence. Name some of the standard Business Intelligence tools in the market. Explain the Dashboard in the business intelligence. SAS Business Intelligence. Explain the SQL Server 2005 Business Intelligence components.......... Business object interview questions  Explain the concepts and capabilities of Business Object. What is Business object agent? What is broad cast agent? Explain the functional differences between BO and COGNOs. What is a universe? Explain the types of universes in business objects. What is security domain in Business Objects?............ Business object interview questions Differentiate between Data Mining and Data warehousing. What is Data purging? What are CUBES? What are OLAP and OLTP? What are the different problems that “Data mining” can solve? What are different stages of “Data mining”?..................... OLAP interview questions Explain the concepts and capabilities of OLAP. Explain the functionality of OLAP. What are MOLAP and ROLAP? Explain the role of bitmap indexes to solve aggregation problems. Explain the encoding technique used in bitmaps indexes. What is Binning? What is candidate check?.................. More datawarehousing interview questions - March 22, 2010 at 15:20 PM by Kshipra What is a data warehouse? What are its qualities? What are the components of datawarehouse? Explain: a.) Multidimensional Database b.) Relational Database     How would you decide on using them? Define Datamarts. Is it preferable to load data from datawarehouse to datamarts or otherwise. Why? How would you purge data from cache in different ways? What are database triggers? How would you manage them in DWH? Explain SCD. What are the different methods to capture them? Explain: a.) E-R modeliing b.) Dimensional Modelling c.) Semi addictive facts d.) Hierarchies e.) Level Explain: a.)OLAP b.) Datawarehouse c.) ODS d.) OLTP  What do you mean by a fact less fact table? What do you mean by snapshot? Why is denormalization promoted in Universe Designing? Will you be able to load a fact table if its star index is gets corrupted? If yes, how? What do you mean by non-addictive facts? What are different types of OLAP technologies? List advantages and disadvantages of each. What are the various architectures of data warehouse? Which is used where? Is there a difference between data warehousing and business intelligence? If yes, what? Compare data warehouse and operational data.