I have had the same problem twice now inside 1 month.
Randomly I get the "Error establishing Database connection" message.
And when I go to my WP backend, I have the option to click "repair the database" button that fixes the problem.
On the Database Repair page it still says:
Some database problems could not be repaired...
wp_users: 4 clients are using or haven't closed the table properly
wp_usermeta: 4 clients are using or haven't closed the table properly
wp_posts: 4 clients are using or haven't closed the table properly
wp_comments: 4 clients are using or haven't closed the table properly
wp_options: Table is marked as crashed
wp_postmeta: 4 clients are using or haven't closed the table properly
wp_terms: 4 clients are using or haven't closed the table properly
wp_term_taxonomy: 4 clients are using or haven't closed the table properly
wp_term_relationships: 4 clients are using or haven't closed the table properly
wp_commentmeta: 4 clients are using or haven't closed the table properly
Is there something I can do to fix these problems??
My Wordpress is working fine now but I am sure that eventually I will get that "Error Establishing Database connection" message again.