Class Three Flashcards
What is Tableau
BI and Analytics platform that helps eople see patterns in Data
VizQL
Visual Query Language
Tableau requires external data
You can never enter any data
Logical Layer
Relationship Canvas
- Relationship donated by the lines
This is the default view in the
Data Source page
- You combine data in this layer
using relationships
- This is the Relationships
(noodles) canvas
Physical Layer
Joins and Unions canvas
- Relationship dennoted by the venn diagram
- You combine data between
tables in this layer using joins and
unions - Each logical table contains at
least one physical table - This is the Joins/Unions canvas
4 ways to join data sources
- Relationships (Relationship View)
- Joins (physical view)
- Unions (Physical view): this makes a table TALLER!!! not wider
- Blends (Worksheet View): approach to combine data from multiple varities of sources and display them on singl screen after aggregation
INNER JOIN
FULL Outer join
Left join
right join
returns the records that are in both tables
returns all records
returns all records in left table
Returns all recorrds in the right table
pill
column of data u drag into vis
Dimnsion
field that is vonsidered indep vbl
categorical is usually measure
Measure
fild that is a dependant vbl
value is a function of one+ dim! usually quantitiative data is measure
A DATA IS EITHER:
DIMENSION OR MEASURE!!!
tableau automatically decides but you can change it
if youre connecting to data in a database… the data might be changing all the time
so you can either want or not want the data to update regularly
LIVE: real time data
EXTRACT: A snap shot of the data that is copied to your local hard drive and it wont change (good for large datasets that are on a server)
Dashboard
we bring different sheets together & play with formatting
Relationships
(Relationship view)
Creates a relationship between tables based on a common
field. Does not merge the data, but keeps it separate.
ASK HOW TO GET THE IMAGE INTO THE DASHBOARD
Joins
(Physical view)
An approach to merge data from the same source (also based
on a common field). Aggregates the data
Unions
(Physical view)
Another approach to merge data. However, unions append the
related fields as rows in the merged dataset
Blends
(Worksheet view)
An approach to combine data from multiple varieties of
sources and display them on a single screen after aggregation.
