MC	Which statement is CORRECT?	A key distinguishing property of a data lake is that it stores raw data in its native format which could be structured, unstructured or semi-structured.	correct	A data lake is less agile compared to a data warehouse which has no structure.	incorrect	A data lake is targeted towards decision makers at middle and top management level, whereas a data warehouse requires a data scientist, which is a more specialized profile in terms of data handling and analysis.	incorrect	In case of a data warehouse, the data schema definitions are only determined when the data is read (schema-on-read) whereas for data lakes it is fixed when the data is loaded (schema-on-write).	incorrect	
MC	In terms of data manipulation, a data warehouse focusses on...	Select/Update statements	incorrect	Insert/Update/Delete/Select statements	incorrect	Delete statements	incorrect	Insert/Select statements	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	Query and reporting tools are an essential component of a comprehensive business intelligence solution.	incorrect	A pivot or cross-table is a popular data summarization tool.  It essentially cross-tabulates a set of dimensions.	incorrect	
MC	Which statement is CORRECT?	Roll-up (or drill-up) refers to aggregating the current set of fact values within or across one or more dimensions.	incorrect	Roll-down (or drill-down) de-aggregates the data by navigating from a lower level of detail to a higher level of detail.	incorrect	Slicing represents the operation whereby one of the dimensions is set at a particular value.	incorrect	Dicing corresponds to a range selection on one or more dimensions.	incorrect	All statements are correct	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	Query and reporting tools are an essential component of a comprehensive business intelligence solution.	incorrect	A pivot or cross-table is a popular data summarization tool.  It essentially cross-tabulates a set of dimensions.	incorrect	
MC	Which statement is NOT CORRECT?	Relational OLAP (ROLAP) stores the data in a relational data warehouse, which can be implemented using a star, snowflake or fact constellation schema.	incorrect	MOLAP scales better to more dimensions than ROLAP.  The query performance may however be inferior to ROLAP unless some of the queries are materialized or high-performance indexes are defined.	correct	Hybrid OLAP (HOLAP) tries to combine the best of both MOLAP and ROLAP.  An RDBMS can then be used to store the detailed data in a relational data warehouse whereas the pre-computed aggregated data can be kept as a multidimensional array managed by a MDBMS.	incorrect	Multidimensional OLAP (MOLAP) stores the multidimensional data using a Multidimensional DBMS (MDBMS) whereby the data is stored in a multi-dimensional array-based data structure optimized for efficient storage and quick access.	incorrect	
MC	Which statement is NOT CORRECT?	A virtual data warehouse (sometimes also called a federated database) or virtual data mart contains no physical data but provides a uniform and consolidated single point of access to a set of underlying physical data stores.	incorrect	A key advantage of virtualization is that it requires no extra processing capacity from the underlying (operational) data stores.	correct	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	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	
MC	In terms of data manipulation, a data warehouse focusses on...	Insert/Update/Delete/Select statements	incorrect	Select/Update statements	incorrect	Delete statements	incorrect	Insert/Select statements	correct	
MC	In terms of data manipulation, a data warehouse focusses on...	Select/Update statements	incorrect	Insert/Update/Delete/Select statements	incorrect	Insert/Select statements	correct	Delete statements	incorrect	
MC	Which of the following is not a characteristic of a data warehouse?	Volatile	correct	Time-variant	incorrect	Integrated	incorrect	Subject-oriented	incorrect