That was smooth! You were able to add your first database and table to Superset. Now, it's time for the fun part, which is visualizing and analyzing the data. In Table, we will find the bigquery-public-data.stackoverflow.posts_questions listed as follows:
When you click on it, it will take you to the chart UI:
Here, we will make a time series plot of the number of questions posted by year. In the Data tab, the Time section is used to restrict data by a temporal column value. We do not want to restrict data for the time series plot. We can clear the Since field.
In order to add axis labels to the line chart, select the Style tab and add descriptions in the X Axis Label and Y Axis Label fields:
Set year as Time Grain and COUNT(*) as the Metrics. Finally, hit Run Query:
We have our first visualization! We can see how the number of questions grew quickly from 2008-2013. Now, Save the visualization, so that we can add it to our dashboard later: