MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred
Query: SELECT value,exptime FROM `wiki_deobjectcache` WHERE keyname='usr_web4_1-wiki_de:messages:de'
Function: MediaWikiBagOStuff::_doquery
Error: 1033 Incorrect information in file: './usr_web4_1/wiki_deobjectcache.frm' (localhost)
' in /var/www/web4/html/includes/db/Database.php:636
Stack trace:
#0 /var/www/web4/html/includes/db/Database.php(591): Database->reportQueryError('Incorrect infor...', 1033, 'SELECT value,ex...', 'MediaWikiBagOSt...', false)
#1 /var/www/web4/html/includes/BagOStuff.php(454): Database->query('SELECT value,ex...', 'MediaWikiBagOSt...')
#2 /var/www/web4/html/includes/BagOStuff.php(324): MediaWikiBagOStuff->_doquery('SELECT value,ex...')
#3 /var/www/web4/html/includes/BagOStuff.php(240): SqlBagOStuff->_query('SELECT value,ex...', 'usr_web4_1-wiki...')
#4 /var/www/web4/html/includes/MessageCache.php(245): SqlBagOStuff->get('usr_web4_1-wiki...')
#5 /var/www/web4/html/includes/MessageCache.php(589): MessageCache->load('de')
#6 /var/www/web4/html/includes/MessageCache.php(526): MessageCache->getMsgFromNamespace('Gadgets-definit...', 'de')
#7 /var/www/web4/html/includes/GlobalFunctions.php(583): MessageCache->get('gadgets-definit...', true, true)
#8 /var/www/web4/html/includes/GlobalFunctions.php(548): wfMsgGetKey('gadgets-definit...', true, true, false)
#9 /var/www/web4/html/includes/GlobalFunctions.php(510): wfMsgReal('gadgets-definit...', Array, true, true, false)
#10 /var/www/web4/html/extensions/Gadgets/Gadgets.php(85): wfMsgForContentNoTrans('gadgets-definit...')
#11 /var/www/web4/html/extensions/Gadgets/Gadgets.php(242): wfLoadGadgetsStructured()
#12 [internal function]: wfGadgetsInjectMessages()
#13 /var/www/web4/html/includes/Hooks.php(117): call_user_func_array('wfGadgetsInject...', Array)
#14 /var/www/web4/html/includes/MessageCache.php(785): wfRunHooks('LoadAllMessages')
#15 /var/www/web4/html/includes/specials/SpecialStatistics.php(28): MessageCache->loadAllMessages()
#16 /var/www/web4/html/includes/SpecialPage.php(539): SpecialStatistics->execute(NULL)
#17 /var/www/web4/html/includes/Wiki.php(226): SpecialPage::executePath(Object(Title))
#18 /var/www/web4/html/includes/Wiki.php(59): MediaWiki->initializeSpecialCases(Object(Title), Object(OutputPage), Object(WebRequest))
#19 /var/www/web4/html/wiki(114): MediaWiki->initialize(Object(Title), NULL, Object(OutputPage), Object(User), Object(WebRequest))
#20 {main}

Exception caught inside exception handler: exception 'DBQueryError' with message 'A database error has occurred
Query: SELECT page_title FROM `wiki_depage` WHERE page_is_redirect = '0' AND page_namespace = '8' AND (page_title not like '%%/%%') AND (page_len > 10000)
Function: MessageCache::loadFromDB
Error: 1033 Incorrect information in file: './usr_web4_1/wiki_depage.frm' (localhost)
' in /var/www/web4/html/includes/db/Database.php:636
Stack trace:
#0 /var/www/web4/html/includes/db/Database.php(591): Database->reportQueryError('Incorrect infor...', 1033, 'SELECT page_ti...', 'MessageCache::l...', false)
#1 /var/www/web4/html/includes/db/Database.php(1001): Database->query('SELECT page_ti...', 'MessageCache::l...')
#2 /var/www/web4/html/includes/MessageCache.php(339): Database->select('page', 'page_title', Array, 'MessageCache::l...')
#3 /var/www/web4/html/includes/MessageCache.php(268): MessageCache->loadFromDB('de')
#4 /var/www/web4/html/includes/MessageCache.php(589): MessageCache->load('de')
#5 /var/www/web4/html/includes/MessageCache.php(526): MessageCache->getMsgFromNamespace('Databaseerror', 'de')
#6 /var/www/web4/html/includes/GlobalFunctions.php(583): MessageCache->get('databaseerror', true, false)
#7 /var/www/web4/html/includes/GlobalFunctions.php(548): wfMsgGetKey('databaseerror', true, false, true)
#8 /var/www/web4/html/includes/Exception.php(70): wfMsgReal('databaseerror', Array)
#9 /var/www/web4/html/includes/db/Database.php(2617): MWException->msg('databaseerror', 'Database error')
#10 /var/www/web4/html/includes/Exception.php(201): DBQueryError->getPageTitle()
#11 /var/www/web4/html/includes/Exception.php(164): MWException->htmlHeader()
#12 /var/www/web4/html/includes/Exception.php(183): MWException->reportHTML()
#13 /var/www/web4/html/includes/Exception.php(269): MWException->report()
#14 /var/www/web4/html/includes/Exception.php(327): wfReportException(Object(DBQueryError))
#15 [internal function]: wfExceptionHandler(Object(DBQueryError))
#16 {main}