First, we need to define a Data Source. A Data Source is a place where our data resides; it can be an RDBMS (such as MySQL or Postgres), a comma-separated text file, a document store, and so on (these features will be covered in Chapter 4, Connecting to Data Sources).
For this chapter, we will be using Redash's internal PostgreSQL (the same example will work as is for any SQL queriable Data Source), to be able to execute parts of this specific example, you must have the dockerized PostgreSQL server set up.
In case you don't have any Data Source set up yet, but you still wish to explore Redash and continue through this chapter, skip the PostgreSQL definition, and move to Alternative Static Data Source Definition right after it.
To validate that your dockerized PostgreSQL is up and running execute the following command:
docker ps
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