When the creation of database is included in the commonly running code, sometimes this part of code can be very huge. Also these will not be executed when the program found the database exists already, this will still waste some time when this part is parsing. These database creation code can be see

The idea begins when I see hash index is only for MEMORY/HEAP/NDB, and PHP array is a simple hash table.

Sometimes, we use MYSQL to store enumerable values. However, it is not that easy to change available values for these fields. Instead, we create another table to store those availables values, ass