Top Data Warehouse General Interview Questions :: ALLInterview.com http://www.allinterview.com Top Data Warehouse General Interview Questions en-us When should you use a STAR and when a SNOW-FLAKE schema? http://www.allinterview.com/showanswers/14115.html The snowflake and star schema are methods of storing data which are multidimensional in nature (i.e. which can be analysed by any or all of a number of independent factors) in a relational database. The snowflake schema (sometimes called snowf what is the difference between aggregate table and fact table ? how d http://www.allinterview.com/showanswers/32079.html fact table is one which contains all the facts (measures).aggregate table is one which is created after the cube is processed.this aggregate table contains human unreadable text. how can one connect two fact tables ? is it possible ? how? http://www.allinterview.com/showanswers/32226.html This confirm dimenstion methodology.If a dimension table is connected to more then one Fact table is called confirm dimension. what are the types of dimension tables http://www.allinterview.com/showanswers/14105.html 1. Dimension 2. Detail 3. Measure What is the difference between OLAP, ROLAP, MOLAP and HOLAP? http://www.allinterview.com/showanswers/14110.html OLAP: Online analytical process. For analysis. ROLAP: Relational Online analytical processing. MOLAP: Multi dimensional analytical process. HOLAP: Hybrid Online analytical process. What is Data purging? http://www.allinterview.com/showanswers/8532.html Information sources may be unreliable and may purge data. On the other hand, information at the warehouse is under the control of the warehouse users; it can be stored safely and reliably for as long as necessary. Hierarchy of DWH? http://www.allinterview.com/showanswers/8482.html Data modeling ETL process BI process What is the difference between a data warehouse and a data mart? http://www.allinterview.com/showanswers/14108.html Dataware house: It is a collection of data marts. Represents historical data. Data mart: It is a sub set of data ware housing. It can provide the data to analyze query reporting & analysis. wht is degenerated dimension ?it's uses? http://www.allinterview.com/showanswers/58622.html degenerated dimension is data that is dimensional in nature but stored in a fact table Where can one get more info about Data Warehousing? http://www.allinterview.com/showanswers/14119.html I think, the book ?Data Warehousing Tool Kit" by R.Kimbal is the best one to have information about data warehousing. It has got a very generic way of stepping in to fundamentals of Data Warehousing and the process to build a data warehou What is a star schema? Why does one design this way? http://www.allinterview.com/showanswers/14114.html The star schema (sometimes referenced as star join schema) is the simplest data warehouse schema, consisting of a single "fact table" with a compound primary key, with one segment for each "dimension" and with additional col Difference between ODS and Staging http://www.allinterview.com/showanswers/57117.html An operational data store (ODS) is a type of database often used as an interim area for a data warehouse. Unlike a data warehouse, which contains static data, the contents of the ODS are updated through the course of business operations. An O How can Oracle Materialized Views be used to speed up data warehouse http://www.allinterview.com/showanswers/14117.html In oracle materialized view carry the carry with them so it is easy 7 faster to retrieve the data for reporting instead of goin to the actual database these provide the faster retrieval of data. How many repositories can we create in Informatica? http://www.allinterview.com/showanswers/8483.html unlimited i think..anyone plz correct me if i am wrong.. what is the difference between etl tool and olap tools http://www.allinterview.com/showanswers/14104.html etl tool means extract,transform and load the data into the ware house.based on this data by using olap tool we can generate reports