MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred
Query: SELECT page_id,page_len,page_is_redirect FROM `wiki_jppage` WHERE page_namespace = '0' AND page_title = 'メインページ' LIMIT 1
Function: LinkCache::addLinkObj
Error: 1033 Incorrect information in file: './usr_web4_1/wiki_jppage.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...', 'LinkCache::addL...', false)
#1 /var/www/web4/html/includes/db/Database.php(1001): Database->query('SELECT page_id...', 'LinkCache::addL...')
#2 /var/www/web4/html/includes/db/Database.php(1081): Database->select('page', Array, Array, 'LinkCache::addL...', Array, Array)
#3 /var/www/web4/html/includes/LinkCache.php(167): Database->selectRow('page', Array, Array, 'LinkCache::addL...', Array)
#4 /var/www/web4/html/includes/Title.php(1886): LinkCache->addLinkObj(Object(Title))
#5 /var/www/web4/html/includes/Article.php(499): Title->getArticleID()
#6 /var/www/web4/html/includes/Article.php(364): Article->getID()
#7 /var/www/web4/html/includes/Article.php(3036): Article->loadPageData()
#8 /var/www/web4/html/includes/Article.php(696): Article->checkTouched()
#9 /var/www/web4/html/includes/Wiki.php(447): Article->view()
#10 /var/www/web4/html/includes/Wiki.php(63): MediaWiki->performAction(Object(OutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#11 /var/www/web4/html/wiki(114): MediaWiki->initialize(Object(Title), Object(Article), Object(OutputPage), Object(User), Object(WebRequest))
#12 {main}

Exception caught inside exception handler: exception 'DBUnexpectedError' with message 'Error in fetchRow(): Incorrect information in file: './usr_web4_1/wiki_jpprotected_titles.frm' (localhost)' in /var/www/web4/html/includes/db/Database.php:782
Stack trace:
#0 /var/www/web4/html/includes/Title.php(1291): Database->fetchRow(false)
#1 /var/www/web4/html/includes/Title.php(1783): Title->getTitleProtection()
#2 /var/www/web4/html/includes/Title.php(1828): Title->loadRestrictions()
#3 /var/www/web4/html/includes/Title.php(1176): Title->getRestrictions('edit')
#4 /var/www/web4/html/includes/Title.php(995): Title->getUserPermissionsErrorsInternal('edit', Object(User), false)
#5 /var/www/web4/html/includes/Title.php(967): Title->userCan('edit', false)
#6 /var/www/web4/html/includes/OutputPage.php(913): Title->quickUserCan('edit')
#7 /var/www/web4/html/includes/Exception.php(159): OutputPage->output()
#8 /var/www/web4/html/includes/Exception.php(183): MWException->reportHTML()
#9 /var/www/web4/html/includes/Exception.php(269): MWException->report()
#10 /var/www/web4/html/includes/Exception.php(327): wfReportException(Object(DBQueryError))
#11 [internal function]: wfExceptionHandler(Object(DBQueryError))
#12 {main}