larsstr

Now, I got the relevanssi_content_to_index hook working. My code is the following:

function add_extra_content($content) {
    global $wpdb, $post;
    $content = $wpdb->get_col("SELECT meta_value FROM arowp_postmeta WHERE post_id = $post->ID AND meta_key LIKE 'beitragskapitel_%_headline' AND meta_key NOT LIKE 'beitragskapitel_%_erweiterung_headline'");
    return implode(" ", $content);
}

add_filter('relevanssi_content_to_index', 'add_extra_content');

If I print $content all the headlines are imploded into a single string. But unfortunately, it seems that the weighing is unchanged. The order of my results are the same as before. I tried to add the add_filter([...]) command multiple times but that effects nothing. Do you have a solution for that? If it is easier with the premium version, it would not be a problem to buy that version :).

Again, thank you very much for your stunning support!

Mikko, thank you very much for your fast answer. I read the explanation of relevanssi_content_to_index hook (indexing-additional-content) but I’m not sure that this fits the requirements. There are a lot of posts on my site which consists of many data sets, constructed through the repeater field of ACF. So there can be multiple headlines on a side, which are generated with every data set from the repeater field.
When I understand that hook, I have to manually declare every headline for every post (because of two parameters). Is there no dynamic solution?
If the premium version is relevant, i would immediately buy it.

Wow! I’m impressed by your support speed and quality.
I took your second advice, added a mysql-parameter to limit the output by a given maximum of values and now it works like a charm!

For all interested people, here is my modified version (added output limitation by a given value as argument) of Héctor’s wonderful solution advice:

if(!function_exists("get_popular_post_ids")) {
	function get_popular_post_ids($args) {
		global $wpdb;
		$prefix = $wpdb->prefix . "popularposts";
		$where = "";
		$now = current_time('mysql');

		/* Build the Query */
		$fields = "p.ID AS 'id', p.post_title AS 'title', p.post_date AS 'date', p.post_author AS 'uid', v.pageviews AS 'pageviews'";

		$from = "{$prefix}data v LEFT JOIN {$wpdb->posts} p ON v.postid = p.ID";

		switch( $args['range'] ){
			case "yesterday":
				$where .= " AND p.post_date > DATE_SUB('{$now}', INTERVAL 1 DAY) ";
				break;

			case "daily":
				$where .= " AND p.post_date > DATE_SUB('{$now}', INTERVAL 1 DAY) ";
				break;

			case "weekly":
				$where .= " AND p.post_date > DATE_SUB('{$now}', INTERVAL 1 WEEK) ";
				break;

			case "monthly":
				$where .= " AND p.post_date > DATE_SUB('{$now}', INTERVAL 1 MONTH) ";
				break;

			default:
				$where .= "";
				break;
		}

		if(is_numeric($args['num'])) {
			$num = " LIMIT ".$args['num'];
		} else {
			$num = "";
		}

		$where .= " AND p.post_type = 'post'";
		$where .= " AND p.post_password = '' AND p.post_status = 'publish'";	

		$orderby = "ORDER BY pageviews DESC";

		$query = "SELECT {$fields} FROM {$from} {$where} {$orderby} {$num};";

		$result = $wpdb->get_results($query);

		$counter = 0;
		$myIDs = array();

		foreach ($result as $aPost) {
			$theID = $aPost->id;

			if ( !$theID == "" ) {
				$myIDs[$counter] = $theID;
				$counter++;
			}
		}

		return($myIDs);
	}
}

Thank you very much :)!