[Mediawiki-l] Death by user_groups.MYI?

[Myria]

When I went to check on my Wiki this afternoon I was rather surprised to get
this error message --

___________________________________
A database error has occurred
Query: SELECT ug_group FROM `user_groups` WHERE ug_user = '1'
Function: User::loadFromDatabase
Error: 1017 Can't find file: 'user_groups.MYI' (errno: 2) (localhost)

Backtrace:

    * GlobalFunctions.php line 451 calls wfbacktrace()
    * Database.php line 400 calls wfdebugdiebacktrace()
    * Database.php line 350 calls databasemysql::reportqueryerror()
    * Database.php line 726 calls databasemysql::query()
    * User.php line 693 calls databasemysql::select()
    * User.php line 623 calls user::loadfromdatabase()
    * Setup.php line 209 calls user::loadfromsession()
    * index.php line 63 calls require_once()
______________________________________

Note that going to the site without a cookie set gets you a different and
less informative error (see http://wolfandturtle.net/Indigo).

As of this morning the Wiki was working fine and to the best of my knowledge
nothing has been done to it today. The database appears to be fine, at least
as far as I can tell with a quick glance, as does localsettings and all the
rest, and I've reset the database users just in case (I use two to avoid
problems). Also, other aps I host that use MySQL are running just fine.

The most likely explanation for my woes is my host upgraded
something-or-other and lost/forgot/broke something (this "user_groups.MYI"
file?!?). In case that assumption is wrong and someone here might have a
clue I'm lacking, I figured I'd ask.

Versions -
Wiki -- 1.5rc4 (The Day of the Dead version)
MySQL -- Ver 12.22 Distrib 4.0.16 (The Killer of Wikis version)
PHP -- 4.3.8 (The I Wish I was Ruby on Rails version)

If anyone knows anything about this 'user_groups.MYI' and why it, or the
lack thereof, might have caused my Wiki to join the digital dead, please let
me know.

							Myria