我有一个大的WP站点，有大约2k个帖子和150k个Posteta。当浏览到一个大类别时，归档文件的加载速度非常慢，因为WP查询会首先显示特色帖子。我知道最终的目标是优化Posteta表，但现在我想知道是否有任何可能的方法来优化下面的元查询（底部的一个）。

我做了一些调试（参见//注释），发现“比较”=>“！=”导致查询速度非常慢。我还发现“或”<；\'查询速度大大加快，结果也一样，但我不确定这样做是否合适。请让我知道是否有办法加快此查询。谢谢

function appthemes_addon_on_top_query( $wp_query ){

    $addon_type = $wp_query->get( \'addon_on_top\' );

    if( ! $addon_type || ! appthemes_addon_exists( $addon_type ) ) {
        return;
    }

    $addon_info = appthemes_get_addon_info( $addon_type );
    $flag_key   = $addon_info[\'flag_key\']; //custom field for featured posts
    $meta_query = (array) $wp_query->get( \'meta_value\', 1 );
    $meta_query = array_filter( $meta_query );
    $meta_query[] = array(
        \'relation\' => \'OR\',
        array(
            \'key\'     => $flag_key,
            \'compare\' => \'NOT EXISTS\',
        ),
        array(
            \'relation\' => \'OR\',
            //Deleting the array below makes the query quick, but i need it to show featured posts first
            array(
                \'key\'   => $flag_key,
                \'value\' => 1,
            ),
            //Deleting the array below makes the query quick, but i need it to properly sorting the posts by date (see below: $wp_query->set( \'orderby\')
            array(
                \'key\'     => $flag_key,
                \'value\'   => 1,
                \'compare\' => \'!=\', //It is about this comparison. \'\' or \'<\' makes the query quick, but i am not sure if that is a proper replacement. Also not sure why \'!=\' makes it this slow.
            ),
        ),
    );

    $wp_query->set( \'meta_query\', $meta_query );
    $wp_query->set( \'orderby\', array( \'meta_value\' => \'DESC\', \'date\' => \'DESC\' ) );
}