Phases in Data Analytics
- Data requirement gathering
- Data source identification
- Data cleaning
- Data processing
- Exploratory data
... [Show More] analysis
Types of Analytics
- Descriptive analytics
- Diagnostic analytics
- Predictive analytics
- Cognitive analytics
- Prescriptive analytics
Roles in data science
- Data analyst
- Business analyst
- Data engineer
- Data scientist
- Database admin
Data analyst
- jack of all traits
- PowerBI (minimal/no code)
- PM / stakeholders
Business analyst
- more involved with the business than data
- overlaps with data analyst
- data requirement gathering / data communication
- closer to stakeholders/ decisionmakers
Data engineer
- closer to data
- data source identification/management and data cleaing/processing
Data scientist
- data cleaning / processing, and exploratory data analysis
- perform descriptive, cognitive and predictive analysis
Database administrator
database, but also some security aspects too. specific users have access etc ...
data table VS lookup table
data table = table with (sales) transactions
lookup table = table with product information
Surrogate Key
An artificial column added to a relation to serve as a primary key
Star Schema
The most commonly used and the simplest style of dimensional modeling
(star schemas prefered in PowerBI)
Why Star Schema?
+ Usability
+ Simpler DAX (code)
+ Performance
+ Faster Refreshers
Excel funct. IF is nearly the same as which DAX funct?
IFX
You want to delete a dataset but the PowerBI service will not let you.
Why not?
Probably because the dataset is already being used in a published app.
What tool can you use in PowerBI Desktop to reduce data?
data modeler?
What should you do to increase the readability of a report?
+ Remove unneeded field labels.
+ Select the most appropriate visualization
+ Use borders.
What should you use to highlight a specific visualization in a report?
Spotlight
FB, Twilio, GitHub ect ... are all examples of Power BI ______ ??
Online services
PowerBI works best with tables that are ____ ?
Long and Skinny
You have 2 cols of numerical data and want to create a visual to help determine if there's a relationship between them.
What chart is designed to do this?
Scatter chart
Which DAX funct counts the number of products in the Product data table.
COUNTX
What do you call a visualization that has the single purpose of filtering other visuals in the view?
Slicer
Which type of visualization is best when comparing proportions in large volume of data with multiple categories and subcategories?
Treemap
Data modeler use?
Can be used to reduce data. Views are good for saving state of easy access of report.
Spotlight use?
Good for highlighting specific visualizations in a report.
Scatter charts use?
best for creating a visual to determine if there's a relationship between 2 big columns.
Snowflake schema or Star schema best for PowerBI?
Star schema
What can be used to query data from Azure Analysis Services?
Multidimensional Expressions (MDX)
Data Analysis Expressions (DAX)
using RLS, you can share a single report where users can see different data according to their job role?
(True or False?)
True!
2 ways of implementing RLS in PowerBI?
The static method
The dynamic method.
How to configure RLS for Analysis Services live connection?
Configure Row-Level security on the on-remises model for Analysis Services live connections
You have created RLS roles in PowerBI Desktop using DAX. Where can you assign users to these roles?
In Power BI Service
Max nr of possible lvls for a tree in Decomposition Tree AI visual in PowerBI?
Max nr of levels for the tree is 50.
Max nr of data points that can be visualized at one time on the tree is 5000.
We truncate levels to shop top n.
Current top n per level is set to 10.
Data Lineage
The Path data takes from data source to the destination.
Workspace roles in PowerBI?
1. Admin
2. Member
3. Contributor
4. Viewer
How to optimize query performance in Power BI?
+ Process as much data as possible in the original data source
+ Use native SQL queries
+ Separate date and time
Measures VS Calculations
Measures can be used it different contexts, and are stored in the model as src code, but computed only when it's used in the report.
PowerBI search algorithm?
Binary Search
XML
Extensible Markup Language
JSON
JavaScript Object Notation
SSAS
SQL Server Analysis Services
SSIS
SQL Server Integration Services
SSMS
SQL Server Managment Studio - GUI to manage SQL server
Role Playing Dimension
A table with multiple valid relationships between itself and another table.
Dim table that can slice filter on another table in more than 1 way.
High/normal/low cardinality?
High: primary keys
Normal: Names
Low: True/False
Object-level security (OLS)
Object-level access allows us to hide whole tabs and objects from particular users, so they don't even know that type of data exists.
Object-level access is set with object permissions in user profiles and permission sets.
DPI
Dot Per Inch
(Resolution / Mått på upplösning)
Hur många DPI har visuella Python-objekt?
Alla visuella Python-objekt visas med 72 DPI
Python script begränsningar?
- Data som används vid ritning av visuella Python-objekt är begränsade till 150 000 rader.
- Indata har en gräns på 250 MB.
- Alla visuella Python-objekt visas med 72 DPI
What does the usage metric "Most Consumed Dashboards by Users" include?
A. the person who built the dashboard
B. other people who share the dashboard
C. users who consume the dashboard in a content pack
What is the recommended level of security for data extensions?
Allow only certified extensions to load
In Power BI, what is the most important difference between tables related in a star schema and in a snowflake schema?
A snowflake schema is much less efficient for Power BI.
What are benefits of modifying your Excel data source in the Power Query Editor rather than in Excel?
A. You can track the changes you make.
B. It is less error prone than manual editing.
C. It will not affect other users of the spreadsheet.
What is the primary purpose of the Relationship view in Power BI Desktop?
to relate tables
Why might you use the DAX DIVIDE function rather than a forward slash (/) when creating a measure?
DIVIDE does not raise an error when the denominator is zero
When will links to a web-published report stop working?
approximately one hour after the report is deleted
XMLA
XML for Analysis
OLAP
Online analytical processing [Show Less]