Topic: admin_maintenence.php
$truncate_sql = ($db_type != 'sqlite') ? 'TRUNCATE TABLE ' : 'DELETE FROM ';
$db->query($truncate_sql.$db->prefix.'search_matches') or error('Unable to empty search index match table', __FILE__, __LINE__, $db->error());
$db->query($truncate_sql.$db->prefix.'search_words') or error('Unable to empty search index words table', __FILE__, __LINE__, $db->error());
Shouldn't it truncate search_cache as well?