protected function _deleteInner( $filePath, $fname )
    {
        if ( !$this->_query( "UPDATE " . $this->dbTable( $filePath ) . " SET mtime=-ABS(mtime), expired=1 WHERE name_hash=" . $this->_md5( $filePath ), $fname ) )
            $this->_fail( "Deleting file $filePath failed" );
        return true;
    }