Tableau Basics – Terminologies Part 1
Being a beginner, you may need a few new terminologies, but the most important 2 terms are Dimensions and Measures. Yeah, you would have heard it. Let’s talk about them detailed.
Dimension is a field which defines a category. It can be a place, thing, person, ID (yes, numerical identifier too), date, boolean – TRUE, FALSE etc.
Measure is a field which will be usually a number. A group of numbers whose average can be computed and gives useful information.
First name – Ram, Sham, Rahul
Employee ID – 123, 542, 125
Date – 5/17/2015, 5/5/2015, 1/1/2011
Product ID – APPLE-XR, SAMSUNG-M2-2019, VIVO-12
Salary – 10,000 , 20,000 , 50,000
Age – 10, 44, 23
Distance – 12, 42, 21
As a Tableau Developer, do we need to manually identify which is dimension and measure?? No, Tableau does that for you. Tableau is smart enough to categorize them based on their value and field name. You can change it if you want or if Tableau wrongly categorized a field.
Let’s talk about the numeric ID, identifier. Some beginners feel confusing whether a numeric field is a Dimension or Measure. Take the above employee ID example. When we find average of Employee ID, we donot get any meaningful output. Hence it is a dimension. Tableau usually use the keyword ID in the field name to categorize it as dimension. But feel free to change it any point of time.
Tableau Basics | Tableau Tutorial For Beginners
Tableau Basics – Terminologies Part 2
Tableau’s data type is similar to most of the programming language and other tools. They are straightforward and 6 types. The data types in Tableau are Number (Whole), Number (Decimal), String, Date, Date Time and Boolean.
1. Number (Whole) is also called as integer in Tableau.
1,2, 3, 1000
2. Number (Decimal) is also called as float in Tableau.
1.5, 4.89, 5.01
3. String is all alphanumeric text including special characters.
Apple1, Ball@123, 124-121
4. Date is one of the important data type in Tableau. It will be used a lot. It recognizes all date format. But it is recommended to give in mm/dd/yyyy format. We will see date parse functions in detailed blog of Calculated field.
5. If you have date time field in your data, you could do a lot of analysis like Hourly Trend, time series at minute level, etc
1/1/2017 12:00 AM, 1/3/2019 15:00:00
Boolean is simply 0 and 1 i.e. False and True.
Tableau shows the data type as symbols and icon in the data pane and the data source pane.
Calculated field, Parameters and Filters
Calculated field is the new field created by a Tableau developer inside Tableau. It can be a dimension or measure. They are nothing but derived field written in formula by combining 0 or more measures and dimensions.
Sales + Profit, Sales – 10 % of Sales, First 5 characters of address.
Parameter is the dynamic input from the user. It can be a dropdown, slider, list, text box. Tableau is supporting only single valued parameter as of when this is written. We can use that to dynamically change the value of calculated field and do lots more with parameter.
Enter a value, Top N
Filters are the data limiters in Tableau. You could use that to view specific data.
Filtering 10 years data from 100 years data, filtering to view only sales greater than 100 K.