MC	Which statement is NOT CORRECT?	Decision making at strategic level is usually about day-to-day decisions.	correct	In a fact constellation schema, more than one fact table is used.	incorrect	A data mart is a scaled down version of a data warehouse aimed at meeting the information needs of a homogeneous small group of end-users such as a department or business unit (e.g., marketing, finance, logistics, HR, etc.).	incorrect	Dependent data marts pulls their data from a central data warehouse, whereas independent data marts are standalone systems drawing data directly from the operational systems, external sources or a combination of both.	incorrect	
MC	Which statement is NOT CORRECT?	Slowly changing dimensions in a data warehouse environment can be tackled by overwriting the old value with the new value. This approach can be used to correct data errors.	incorrect	Slowly changing dimensions in a data warehouse environment can be tackled by duplicating records and adding Start_Date, End_Date and Current_Flag attribute types.  This approach only allows to retain partial historical information.	correct	A slowly changing dimension in a data warehouse context is a dimension that changes slowly and irregularly over a period of time.	incorrect	Slowly changing dimensions in a data warehouse environment can be tackled by adding a new attribute type to the table such that only the most recent and previous value of it are stored. 	incorrect	
MC	Which statement is NOT CORRECT?	For slowly changing dimensions, surrogate keys can be handy to store the historical information by duplicating a record and adding, e.g., Start_Date, End_Date and Current_Flag attribute types.	incorrect	Junk dimensions can be defined to efficiently accommodate low cardinality attribute types such as flags or indicators.	incorrect	An outrigger table can be defined to store a set of attribute types of a dimension table which are uncorrelated, high in cardinality and updated simultaneously.	correct	One way to deal with rapidly changing dimensions is by splitting the information into stable and rapidly changing information.  The latter can then be put into a separate mini-dimension table with a new surrogate key.  The connection can then be made by using the fact table or by introducing a new table connecting both.	incorrect	
MC	Which statement is NOT CORRECT?	A pivot or cross-table is a popular data summarization tool.  It essentially cross-tabulates a set of dimensions.	incorrect	A key disadvantage of OLAP is that it does not allow to interactively analyze your data, summarize it and visualize it in various ways.	correct	Query and reporting tools are an essential component of a comprehensive business intelligence solution.	incorrect	The key fundament of OLAP is a multidimensional data model which can be implemented in various ways.	incorrect	
MC	Which statement is NOT CORRECT?	Surrogate keys essentially buffer the data warehouse from the operational environment by making it immune to any operational changes.	incorrect	A snowflake schema normalizes the fact table of a star schema.	correct	A factless fact table is a fact table which only contains foreign keys and no measurement data.	incorrect	A fact constellation schema has more than one fact table which can share dimension tables.	incorrect	
MC	A data warehouse is:	Time-oriented, integrated, time-variant and volatile.	incorrect	Subject-oriented, integrated, time-variant and volatile.	incorrect	Subject-oriented, integrated, time-invariant and non-volatile.	incorrect	Subject-oriented, integrated, time-variant and non-volatile.	correct	
MC	Which statement is NOT CORRECT?	A key disadvantage of OLAP is that it does not allow to interactively analyze your data, summarize it and visualize it in various ways.	correct	The key fundament of OLAP is a multidimensional data model which can be implemented in various ways.	incorrect	A pivot or cross-table is a popular data summarization tool.  It essentially cross-tabulates a set of dimensions.	incorrect	Query and reporting tools are an essential component of a comprehensive business intelligence solution.	incorrect	
MC	Which statement is CORRECT?	A factless fact table contains no measurement data and is therefore useless.	incorrect	When choosing the granularity of the fact table, a trade-off between the level of detailed analysis and storage requirements (and hence query performance) must be made.	correct	A junk dimension can be used for attribute types that are highly correlated, high in cardinality and simultaneously updated.	incorrect	In a fact constellation schema, only one fact table is used.	incorrect	
MC	Which statement is NOT CORRECT?	Surrogate keys are usually larger than business keys to speed up query execution time.	correct	Surrogate keys are typically meaningless integers, used as foreign keys to connect the fact to the dimension tables.	incorrect	Business keys usually have a business meaning that may change over time.	incorrect	Surrogate keys essentially buffer the data warehouse from the operational environment by making it immune to any operational changes.	incorrect	
MC	Which statement is NOT CORRECT?	A virtual data warehouse or virtual data mart can be used to relieve underlying (operational) data sources from intensive processing.	correct	Independent data marts are standalone systems, drawing their data directly from operational systems, external sources or a combination of both. 	incorrect	The data schema definitions in a data lake are only determined when the data are read (schema-on-read) instead of when the data are loaded (schema-on-write) as is the case for a data warehouse. 	incorrect	A data lake stores raw data in its native format, which could be structured, unstructured, or semi-structured. 	incorrect