Power BI important concepts and DAX function
Power
BI is business intelligence tool and data
visualization tool. Power BI connect with different data source like SQL, CSV,
Excel, Website this data used in power BI interactive dashboard and create
analysis report.
Power
BI Version:
1.
Desktop
2.
Service based (Saas)
3.
Mobile power BI apps
4. Power Bi report server
Relationship between BI tool and Data
Warehouse
BI tool take data from data warehouse to
generate the report for end user
Data Warehouse gather of huge amount of data
form single and multiple source.
Data warehouse follow the ETL process
E = Extract the data from single and multiple
source and load into it’s environment.
T= Transform the data according to business
requirement
L= load the data in the targeted table
Power BI Flow
1.
Power BI connect with data source
2.
Transform the data according to business requirements
3.
Load the data into power bi desktop
4.
Building relationship between the data
5. Finally creating report and publish the report
What is power query in power Bi?
Power query is used to manipulate, import and
structure the data into simple form or according to business requirement.
How to open power query in power BI
1. Power BI window Home > Get Data >
Select any data source > Browse the file > “Edit” it open the power query
2. power BI window home > “Edit Queries”
How to change column data type in the power
BI ?
Open the power query in power BI select the
column on right hand sight data type tab is available for change data type of
column.
What is data modelling in Power Bi ?
Data modelling is process which creates
relationship between common columns with different tables.
Data modelling perform custom calculation in existing table which can be used in future visualization.
Schemas in Power BI
There is two schemas present in power Bi Star
schemas and SnowFlake schemas. Power Bi engine work best with
Star Schemas because
·
No looping exists between three or more tables of a data model.
·
Two tables are connected via one active relationship only.
Snow Flake Schemas consist of number of
subpart of dimensional table so many relationship is present between
dimensional table it’s not good for power bi machine to execute the fast
operation.
Star Schemas having direct relation between
fact table and dimension table.
DAX in Power BI
Data analysis expression (DAX) is collection of
operators and functions used to calculate and return one or more value. This
help creating new meaningful information from existing dataset. We can used DAX
for create “Calculated column” and “Measure”.