MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred
Query: SELECT page_id,page_namespace,page_title,page_restrictions,page_counter,page_is_redirect,page_is_new,page_random,page_touched,page_latest,page_len FROM `wiki_depage` WHERE page_namespace = '2' AND page_title = 'Prince_Prancer' LIMIT 1
Function: Article::pageData
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_id...', 'Article::pageDa...', false)
#1 /var/www/web4/html/includes/db/Database.php(1001): Database->query('SELECT page_id...', 'Article::pageDa...')
#2 /var/www/web4/html/includes/db/Database.php(1081): Database->select('page', Array, Array, 'Article::pageDa...', Array, Array)
#3 /var/www/web4/html/includes/Article.php(332): Database->selectRow('page', Array, Array, 'Article::pageDa...')
#4 /var/www/web4/html/includes/Article.php(344): Article->pageData(Object(DatabaseMysql), Array)
#5 /var/www/web4/html/includes/Wiki.php(297): Article->pageDataFromTitle(Object(DatabaseMysql), Object(Title))
#6 /var/www/web4/html/includes/Wiki.php(60): MediaWiki->initializeArticle(Object(Title), Object(WebRequest))
#7 /var/www/web4/html/wiki(114): MediaWiki->initialize(Object(Title), NULL, Object(OutputPage), Object(User), Object(WebRequest))
#8 {main}

Exception caught inside exception handler: 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('Databaseerror', 'de')
#7 /var/www/web4/html/includes/GlobalFunctions.php(583): MessageCache->get('databaseerror', true, false)
#8 /var/www/web4/html/includes/GlobalFunctions.php(548): wfMsgGetKey('databaseerror', true, false, true)
#9 /var/www/web4/html/includes/Exception.php(70): wfMsgReal('databaseerror', Array)
#10 /var/www/web4/html/includes/db/Database.php(2617): MWException->msg('databaseerror', 'Database error')
#11 /var/www/web4/html/includes/Exception.php(201): DBQueryError->getPageTitle()
#12 /var/www/web4/html/includes/Exception.php(164): MWException->htmlHeader()
#13 /var/www/web4/html/includes/Exception.php(183): MWException->reportHTML()
#14 /var/www/web4/html/includes/Exception.php(269): MWException->report()
#15 /var/www/web4/html/includes/Exception.php(327): wfReportException(Object(DBQueryError))
#16 [internal function]: wfExceptionHandler(Object(DBQueryError))
#17 {main}