“By default, digiKam uses SQLite as its back-end for storing
important metadata and thumbnails. But the photo management
application also provides support for the popular MySQL database
engine, and it comes with a database migration tool that can help
you to move your data from SQLite to MySQL. Of course, you might
wonder why you’d want to switch to MySQL when SQLite already does a
good job of managing the data? Using MySQL as digiKam’s database
back-end allows you to store the data on a remote server. This way,
you can use multiple digiKam installations (e.g., on your notebook
and desktop machine) to access and manage your photo collections.
You can also use MySQL tools to back up and analyze digiKam’s
data.“Obviously, to use digiKam with MySQL, you need a MySQL server.
You also have to create two MySQL databases: one for storing photo
metadata (e.g., digikam) and the other for storing thumbnails
(e.g., thumbnails-digikam)”