Exchanging Data Using COPY

In the previous chapter, you learned about the SQL CREATE, INSERT, and DROP operations in the CRUD process. You also learned how to populate the created tables with manually written values or values from other tables. These operations are good enough to work on small datasets inside a database. However, in real-world scenarios, the bulk of the data comes from systems outside of the database. For example, different systems within the same company need to exchange data, and business analysts need to utilize data from external vendors for analytics. This data is usually sent in the form of files. In addition, once you finish your analytical tasks, you also need to share your results with internal teams or external customers. This data sharing is often done using files, too. While it is possible to use SQL statements to read from or write to these files, they are generally slow and are limited in file processing power.

Typically, data transfer is done with...