I am seeing this error message at the end of a really long MySQL query on some of my Contacts - the ones, generally, with whom I have had a lot of interactions:
"MySQL error 1030: Got error 12 from storage engine"

The full error is:

"
Error retrieving Contact list: Query Failed SELECT meetings.id , meetings.name , meetings.status , ' ' contact_name , ' ' contact_id , ' ' contact_name_owner , ' ' contact_name_mod , meetings.date_modified , jt1.user_name assigned_user_name , jt1.created_by assigned_user_name_owner , 'Users' assigned_user_name_mod, ' ' filename , meetings.assigned_user_id , 'meetings' panel_name FROM meetings LEFT JOIN users jt1 ON jt1.id= meetings.assigned_user_id AND jt1.deleted=0 AND jt1.deleted=0 INNER JOIN meetings_contacts ON (meetings.id=meetings_contacts.meeting_id AND meetings_contacts.contact_id='57fffa') where ( meetings_contacts.deleted=0 AND meetings.deleted=0 AND (meetings.status='Held' OR meetings.status='Not Held')) AND meetings.deleted=0 ) UNION ALL ( SELECT tasks.id , tasks.name , tasks.status , CONCAT(IFNULL(contacts.first_name,''),' ',IFNULL(contacts.last_name,'')) contact_name , tasks.contact_id , contacts.assigned_user_id contact_name_owner , 'Contacts' contact_name_mod, tasks.date_modified , jt1.user_name assigned_user_name , jt1.created_by assigned_user_name_owner , 'Users' assigned_user_name_mod, ' ' filename , tasks.assigned_user_id , 'tasks' panel_name FROM tasks LEFT JOIN contacts contacts ON contacts.id= tasks.contact_id AND contacts.deleted=0 AND contacts.deleted=0 LEFT JOIN users jt1 ON jt1.id= tasks.assigned_user_id AND jt1.deleted=0 AND jt1.deleted=0 where ( tasks.contact_id= '57fffa' AND tasks.deleted=0 AND (tasks.status='Completed' OR tasks.status='Deferred')) AND tasks.deleted=0 ) UNION ALL ( SELECT calls.id , calls.name , calls.status , ' ' contact_name , ' ' contact_id , ' ' contact_name_owner , ' ' contact_name_mod , calls.date_modified , jt1.user_name assigned_user_name , jt1.created_by assigned_user_name_owner , 'Users' assigned_user_name_mod, ' ' filename , calls.assigned_user_id , 'calls' panel_name FROM calls LEFT JOIN users jt1 ON jt1.id= calls.assigned_user_id AND jt1.deleted=0 AND jt1.deleted=0 INNER JOIN calls_contacts ON (calls.id=calls_contacts.call_id AND calls_contacts.contact_id='57fffa') where ( calls_contacts.deleted=0 AND calls.deleted=0 AND (calls.status='Held' OR calls.status='Not Held')) AND calls.deleted=0 ) UNION ALL ( SELECT notes.id , notes.name , ' ' status , CONCAT(IFNULL(contacts.first_name,''),' ',IFNULL(contacts.last_name,'')) contact_name , notes.contact_id , contacts.assigned_user_id contact_name_owner , 'Contacts' contact_name_mod, notes.date_modified , ' ' assigned_user_name , ' ' assigned_user_owner , ' ' assigned_user_mod , notes.filename , notes.created_by , 'notes' panel_name FROM notes LEFT JOIN contacts contacts ON contacts.id= notes.contact_id AND contacts.deleted=0 AND contacts.deleted=0 where ( notes.contact_id= '57fffa' AND notes.deleted=0) AND notes.deleted=0 ) UNION ALL ( SELECT emails.id , emails.name , emails.status , ' ' contact_name , ' ' contact_id , ' ' contact_name_owner , ' ' contact_name_mod , emails.date_modified , jt1.user_name assigned_user_name , jt1.created_by assigned_user_name_owner , 'Users' assigned_user_name_mod, ' ' filename , emails.assigned_user_id , 'emails' panel_name FROM emails LEFT JOIN users jt1 ON jt1.id= emails.assigned_user_id AND jt1.deleted=0 AND jt1.deleted=0 INNER JOIN emails_contacts ON (emails.id=emails_contacts.email_id AND emails_contacts.contact_id='57fffa') where ( emails_contacts.deleted=0 AND emails.deleted=0) AND emails.deleted=0 ) ORDER BY date_modified desc LIMIT 0,10::MySQL error 1030: Got error 12 from storage engine
"

I modified the ContactID in the query to protect the "innocent".

Any ideas what this error means, so that I can advise my host? Is it essentially an optimizer warning that is rejecting the query for being overly resource intensive?

Thanks,
K