This happened today when trying to view the front end of a site.
1. I tried to access the wp-admin.
2. A message came up saying one or more tables needed to be repaired.
3. I followed instructions for adding define(‘WP_ALLOW_REPAIR’, true); to the config.php file.
4. I tried again to load wp-admin and was offered the choice to have it attempt database repair.
5. It failed.
6. I went to phpMyAdmin and selected the wp_options table and initiated repair.
7. Happy Ending. All is well again.