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 Query and reporting tools are an essential component of a comprehensive business intelligence solution. 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 The key fundament of OLAP is a multidimensional data model which can be implemented in various ways. incorrect MC Which statement is CORRECT? 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 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 MC Which statement is CORRECT? The dimension tables of a star schema contain the criteria for aggregating the measurement data and will typically be used as constraints to answer queries. correct A junk dimension can be used for attribute types that are highly correlated, high in cardinality and simultaneously updated. incorrect The ETL process is only executed right before the data warehouse is made operational. incorrect In a data warehouse context, an outrigger table can be defined to store a set of attribute types of a dimension table which are not correlated, high in cardinality and updated sequentially. incorrect MC In terms of data manipulation, a data warehouse focusses on... Insert/Select statements correct Insert/Update/Delete/Select statements incorrect Delete statements incorrect Select/Update statements 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 CORRECT? To speed up report generation and avoid time consuming joins in a star schema, the dimension tables need to be normalized. incorrect The dimension tables in a star schema are frequently updated. incorrect A star schema has one large central dimension table which is connected to various smaller fact tables. incorrect The dimension tables of a star schema contain the criteria for aggregating the measurement data and will typically be used as constraints to answer queries. correct MC Which of the following is not a characteristic of a data warehouse? Volatile correct Integrated incorrect Subject-oriented incorrect Time-variant 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 CORRECT? The dimension tables of a star schema contain the criteria for aggregating the measurement data and will typically be used as constraints to answer queries. correct The dimension tables in a star schema are frequently updated. incorrect To speed up report generation and avoid time consuming joins in a star schema, the dimension tables need to be normalized. incorrect A star schema has one large central dimension table which is connected to various smaller fact tables. incorrect MC Which of the following is not a characteristic of a data warehouse? Volatile correct Subject-oriented incorrect Time-variant incorrect Integrated incorrect