How to purge database

Hello, I don’t really know why my Piwik database is so big (more than 50mb).
How can-I delete a part of it in order to keep it light?
Maybe my use of Piwik is not adapted. Can you tell me more?
Thank you.

See Troubleshooting - Analytics Platform - Matomo

Thank you, I already did it but my database is still 48mb large…

After processing / archiving all your reports you could delete all piwik_archive_numeric_* and piwik_archive_blob_* tables. They will be recreated when running the archiving process again and should then be smaller in size.

You could also try to optimize all your Piwik tables manually. Use the MySQL OPTIMIZE TABLE function. See MySQL :: MySQL 5.5 Reference Manual :: OPTIMIZE TABLE Syntax and 301 Moved Permanently.

This is the answer I was looking for. Thank you n0v1.