RegExp trouble with a LONG pattern

Usually the string is long and the pattern is short when doing a Reqular Expression code, but this time is the other way around. I have a short text of about 500 characters. In that text I want to find names that match a database of about 47.000 unique names and add a link to the specific name. What is the best way of doing this? I partition the array of names into 64 partitions since the one array is to big to procces as a pattern.

function implode_r ($glue, $pieces){
    $out = "";
    foreach ($pieces as $piece){
        if (is_array ($piece)){
            $out .= implode_r ($glue, $piece); // recurse
        }
        else{
            if(strlen($piece)>1){
                $piece = str_replace("(", "(", $piece);
                $piece = str_replace(")", ")", $piece);
                $piece = str_replace("[", "[", $piece);
                $piece = str_replace("]", "]", $piece);
                $piece = str_replace(":", ":", $piece);
                $piece = str_replace(".", ".", $piece);
                $piece = str_replace(",", ",", $piece);
                $piece = str_replace("'", "'", $piece);
                $piece = str_replace("&", "&", $piece);
                $piece = str_replace("?", "?", $piece);
                $piece = str_replace("!", "!", $piece);
                $piece = str_replace("<", "<", $piece);
                $piece = str_replace(">", ">", $piece);
                $piece = str_replace("{", "{", $piece);
                $piece = str_replace("}", "}", $piece);
                $out .= $glue.$piece;
            }
        }
    }
    return $out;
}

function partition( $list, $p ) {
    $listlen = count( $list );
    $partlen = floor( $listlen / $p );
    $partrem = $listlen % $p;
    $partition = array();
    $mark = 0;
    for ($px = 0; $px < $p; $px++) {
        $incr = ($px < $partrem) ? $partlen + 1 : $partlen;
        $partition[$px] = array_slice( $list, $mark, $incr );
        $mark += $incr;
    }
    return $partition;
}

add_filter( 'the_content', 'find_names_in_text');
add_filter( 'get_the_content', 'find_names_in_text');
function find_names_in_text($content){
    global $wpdb;
    $thenames = $wpdb->get_results("SELECT post_title FROM $wpdb->posts WHERE post_type='dogs' GROUP BY post_title", ARRAY_N);
    $namesparts = partition($thenames, 64);
    foreach($namesparts as $part){
        $pattern = implode_r("|", $part);
        $content = preg_replace("(".$pattern.")", "<a href='$1'>$1</a>", $content);
    }
    return $content;
}