Study questions Flashcards
Geoffrey is a data modeler at Adventure Works who developed a DirectQuery model that connects to the data warehouse. To improve the query performance of higher-grain sales queries, Geoffrey added an import aggregation table. What else should Geoffrey do to improve query performance of the higher-grain queries?
Set related dimension tables to dual storage mode
Breana is a data modeler at Adventure Works who developed a manufacturing model, which is an import model. Breana needs to ensure that manufacturing reports deliver real-time results. Which type of table should Breana create?
Hybrid table
Mousef is a business analyst at Adventure Works who wants to create a new model by extending the sales dataset, which is delivered by IT. Mousef wants to add a new table of census population data sourced from a web page. Which model framework should Mousef use?
Composite
Model frameworks:
Import, DirectQuery, composite
Define Hybrid Table
Power BI adds a DirectQuery partition for the current period
T/F You can covert a DirectQuery table to an import table.
TRUE
T/F You can covert an import table to a DirectQuery table.
FALSE
In a Power BI Desktop model design, which type of object do you create to enforce row-level security?
Role
Which of the following statements is correct regarding a star schema design?
Fact table store accumulations of business events
In what order does an analytic query implement its phases?
Filter, Group, Summarize
A good data model offers the following benefits:
Data exploration is faster.Aggregations are simpler to build.Reports are more accurate.Writing reports takes less time.Reports are easier to maintain in the future.
What does data granularity mean?
Data granularity indicates the level the detail within the data, so the higher the granularity, the more detail that is represented in the data.
What is the difference between a fact table and a dimension table?
Fact tables contain observational data while dimension tables contain information about specific entities within the data.
Choose the best answer to explain relationship cardinality?
Cardinality is the measure of unique values in a table.
What is a fully qualified column?
A column that has been identified with both the column and table name.
When should you use the DIVIDE function?
When the denominator is an expression that could return zero or BLANK.
You’re using Power BI Desktop to develop a model. It has a table named Sales, which includes a column named CustomerKey. In reports, you need a calculation to show the number of different customers who have placed orders. What type of DAX calculation will you add to the model?
Measure
You’re using Power BI Desktop to develop a model. It has a table named Customer, which includes a column named DateOfBirth. In reports, you need to group customers by current age. What type of DAX calculation will you add to the Customer table?
Calculated Column
You’re using Power BI Desktop to develop a model. It has a table named Geography, which has two relationships to the Sales table. One relationship filters by customer region and the other filters by sales region. You need to create a role-playing dimension so that both filters are possible. What type of DAX calculation will you add to the model?
Calculated table
You write a DAX formula that adds BLANK to the number 20. What will be the result?
20
Which statement about measures is correct?
Measures can reference other measures directly
Which DAX function can summarize a table?
Countrows
Which of the following statements describing similarity of measures and calculated columns in an Import model is true?
They can achieve summarization of model data
Which statement about calculated tables is true?
Calculated tables store data inside the model, and adding them results in a larger model size.
Which statement about calculated columns is true?
Calculated column formulas are evaluated by using row context.
You’re developing a Power BI desktop model that sources data from an Excel workbook. The workbook has an employee table that stores one row for each employee. Each row has a reference to the employee’s manager, which is also a row in the employee table. You need to add several columns to the Employee table in your model to analyze payroll data within the organization hierarchy (like, executive level, manager level, and so on). Which technique will you use to add the columns?
Add calculated