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...
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.
SQL columns can be NULL or NOT NULL. Let’s see what are the good and bad reasons to declare NULL columns.
Vettabase asked the community what is the most dangerous SQL statment. Let’s think a bit about it!
Updating triggers in production without causing a service disruption
Does NULL mean “no value”? Or does it mean “an unknown value”? Its semantics and history are ambiguous and inconsistent.