This screen is accessed from the back-end Joomla! administrator panel. It is used to check and fix any database issues with your website.
This screen checks that your database table structure is up to date with your Joomla programs and lets you try to fix any problems that are found.
In a normal Joomla version update, changes to the database table structure (also called "schema") are done automatically to keep the database version synchronized with the Joomla version. If an update is done manually, or if some part of an automatic update fails, the database schema might not be updated to match the version of the Joomla program files. In this case you will see a list of database problems on the screen. You can normally fix any problems by clicking on the Fix button.
Screen display when database is up to date.
Screen display when the database table structure is not up to date.
At the top right you will see the toolbar:
The functions are:
administrator/components/com_admin/sql/updates) that were not run during the version update. It then re-checks whether or not the database is up to date. If it is successful, the message "Database table structure is up to date" will show.
At the top left, you will see the following five links: