TYPO3 v9 has reached its end-of-life September 30th, 2021 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
Run the Database Analyzer¶
While in the previous step, tables and columns have been changed or added to allow running the upgrade wizards smoothly. The next step gives you the possibility to remove old and unneeded tables and columns from the database.
Use the "Maintenance section" and click "Analyze Database".
You will be able to execute queries to remove these tables and columns so that your database corresponds to the structure required for the new TYPO3 version.
Be careful if you have deliberately added columns and/or tables to your TYPO3 database for your own purposes! Those tables and columns are removed only if you mark them to be deleted of course, but please be careful that you don't delete them by mistake!
TYPO3 does not directly remove tables and fields, but first renames them
with a prefix
zzz_deleted_*. This allows checking whether the fields and
tables really are not needed anymore or were accidentally marked as deleted
by wrong configuration.
When you are sure you aren't going to need them anymore, you can drop them via the wizard.
Select the upgrades you want and press "Execute":
When you then click "Compare current database with specification" again and you only see the message
then all database updates have been applied.