The size of database in “View More Statistics” does not match the size from “Database” tab in Plesk

Problem

• The size of database shown in Home > Domains > example.com > View More Statistics different from Home > Domains > example. com > Databases tab > example_db
• The MySQL/MariaDB database uses InnoDB engine

Cause

The cause is MySQL bug #1341 in which the ibdata (ibd) files grows as it keeps the information about data even after it was deleted from the database.

The bug on the MariaDB side is available here.

The difference in file size is expected for MySQL and MariaDB databases using InnoDB storage engine, because the size in Databases tab is taken from the information_schema table, which is the real size of the database itself and View More Statistics shows the actual size of the /var/lib/mysql/example_db/ directory in the file system:

# du -sh /var/lib/mysql/example_db/
269M /var/lib/mysql/example_db/

Resolution