How You Broke Your Queries

Understanding the reasons behind why your queries are slow and don’t produce the necessary results is an essential skill for both novices and power users alike. After all, we optimize something that’s broken – how can we optimize our queries if we don’t even know what actions of ours broke them? This is what I’ll help you explore in this chapter. This chapter will focus on the essentials of broken queries as well as some things you may not know, so make sure to read it carefully. Not all advice in this chapter may apply to your specific use case either – weigh the ups and downs of my advice, and take from it what you will. If you’re not sure about something, you can always consult the latest version of documentation concerning your specific DBMS or ask your friendly neighborhood DBA.