1. Create a Heroku Project.
2. Install Heroku Connect and Heroku Postgres add-ons.
3. Create a table in Heroku Postgres.
4. Create some data in Heroku Postgres table.
5. In Heroku Connect, go to External Objects tab. Select the table created in Step 3 under Data Sources.
7. Create External Data Source in Salesforce.
9. Select the table so that it creates External object in Salesforce.
10. Create a tab for the External Object.