Performant SQL

So far, you have learned how to create SQL statements for different types of requests. You have also seen that you can achieve the same goal with different queries. In reality, not all SQL statements are equal. Some run faster, some run slower. These days, analyses or queries are increasingly becoming a part of a larger service or product. One such example is a travel advisory system that incorporates the current location with nearby businesses and/or travel sites. For such a system to be effective and provide up-to-date navigation information, the database must be analyzed at a rate that keeps up with the speed of the car and the progress of the journey. Any delays in the analysis would significantly impact the application’s commercial viability.

While it is certainly not the job of a data scientist or data analyst to ensure that the production process and the database are working at optimal efficiency, it is critical that the queries of the underlying analysis...