What is aggregate table and aggregate fact table ... any examples of both?

Data Warehousing Interview Questions and Answers

(Continued from previous question...)

What is aggregate table and aggregate fact table ... any examples of both?

Aggregate tableĀ contains summarised data. The materialized view are aggregated tables.

for ex in sales we have only date transaction. if we want to create a report like sales by product per year. in such cases we aggregate the dateĀ vales into week_agg, month_agg, quarter_agg, year_agg. to retrive date from this tables we use @aggrtegate function.

(Continued on next question...)

Other Interview Questions

• What's A Data warehouse
• What is ODS?
• What is a dimension table?
• What is a lookup table?
• Why should you put your data warehouse on a different system than your OLTP system?
• What are Aggregate tables?
• What is Dimensional Modelling? Why is it important ?
• Why is Data Modeling Important?
• What is data mining?
• What is ETL?
• What does level of Granularity of a fact table signify?
• What is the Difference between OLTP and OLAP?
• What is SCD1 , SCD2 , SCD3?
• Why are OLTP database designs not generally a good idea for a Data Warehouse?
• What is BUS Schema?
• What are the various Reporting tools in the Market?
• What is Normalization, First Normal Form, Second Normal Form , Third Normal Form?
• What is Fact table?
• What are conformed dimensions?
• What are the Different methods of loading Dimension tables?
• What is conformed fact?
• What are Data Marts?
• What is a level of Granularity of a fact table?
• How are the Dimension tables designed?
• What are non-additive facts?
• What type of Indexing mechanism do we need to use for a typical datawarehouse?
• What Snow Flake Schema?
• What is real time data-warehousing?
• What are slowly changing dimensions?
• What are Semi-additive and factless facts and in which scenario will you use such kinds of fact tables?
• Differences between star and snowflake schemas?
• What is a Star Schema?
• What is a general purpose scheduling tool?
• What is ER Diagram?
• Which columns go to the fact table and which columns go the dimension table?
• What are modeling tools available in the Market?
• Name some of modeling tools available in the Market?
• How do you load the time dimension?
• Explain the advanatages of RAID 1, 1/0, and 5. What type of RAID setup would you put your TX logs.
• What are the vaious ETL tools in the Market?
• What is VLDB?
• What are Data Marts ?
• What are the steps to build the datawarehouse ?
• What is Difference between E-R Modeling and Dimentional Modeling.?
• Why fact table is in normal form?
• What are the advantages data mining over traditional approaches?
• What are the vaious ETL tools in the Market?
• What is a CUBE in datawarehousing concept?
• What is data validation strategies for data mart validation after loading process ?
• what is the datatype of the surrgate key ?
• What is degenerate dimension table?
• What is Dimensional Modelling?
• What are the methodologies of Data Warehousing.?
• What is a linked cube?
• What is the main difference between Inmon and Kimball philosophies of data warehousing?
• What is Data warehosuing Hierarchy?
• What is the main differnce between schema in RDBMS and schemas in DataWarehouse....?
• What is hybrid slowly changing dimension?
• What are the different architecture of datawarehouse?
• what is incremintal loading? 2.what is batch processing? 3.what is crass reference table? 4.what is aggregate fact table?
• what is junk dimension? what is the difference between junk dimension and degenerated dimension?
• What are the possible data marts in Retail sales.?
• What is the definition of normalized and denormalized view and what are the differences between them?
• What is meant by metadata in context of a Datawarehouse and how it is important?
• Differences between star and snowflake schemas?
• Difference between Snow flake and Star Schema. What are situations where Snow flake Schema is better than Star Schema to use and when the opposite is true?
• What is VLDB?
• What's the data types present in bo?n what happens if we implement view in the designer n report
• Can a dimension table contains numeric values?
• What is the difference between view and materialized view?
• What is surrogate key ? where we use it expalin with examples
• What is ER Diagram?
• What is aggregate table and aggregate fact table ... any examples of both?
• What is active data warehousing?
• Why do we override the execute method is struts? Plz give me the details?
• What is the difference between Datawarehousing and BusinessIntelligence?
• What is the difference between OLAP and datawarehosue?
• What is fact less fact table? where you have used it in your project?
• Why Denormalization is promoted in Universe Designing?
• What is the difference between ODS and OLTP?
• What is the difference between datawarehouse and BI?
• Is OLAP databases are called decision support system ??? true/false?
• explain in detail about type 1, type 2(SCD), type 3 ?
• What is snapshot?
• What is the difference between datawarehouse and BI?
• What are non-additive facts in detail?