The most widely known query optimisation rule is that developers should always avoid SELECT *. Even when all columns are needed, they should list their names, because more columns could be created in the future. But developers find this really Continua a leggere How slow is SELECT * ?
Reducing the number of queries is important with any DBMS. There are two reasons for this: reducing the latency of applications; and reducing the workload for the database servers. Continua a leggere MariaDB/MySQL: use SQL properly to run less queries
SQL columns can be NULL or NOT NULL. Let’s see what are the good and bad reasons to declare NULL columns. Continua a leggere When to use NULLable columns in relational databases
Updating triggers in production without causing a service disruption Continua a leggere Updating triggers in production with MariaDB and MySQL
Does NULL mean “no value”? Or does it mean “an unknown value”? Its semantics and history are ambiguous and inconsistent. Continua a leggere What does NULL mean in SQL?