Returning random rows in a random order from a relational database is a very hard problem. In this article we will see an antipattern, we will discuss why this problem is so hard, and we’ll examine some imperfect solutions.
One of the trickiest problems in SQL is to query rows in tranches. This is typically needed in a website search, or in a dynamic catalogue where products appear as you scroll down. You want the DBMS to only return …
Do you want to improve your application’s and database server’s performance? Remove useless queries. Yes, you probably have them.
Why developers need to learn the basics of query optimisation. How to make the learning process easy and pleasant.
It is quite common to use an equality condition and an IS NULL condition on the same columns. Unfortunately, this could make queries very slow.