php scanning content for specific keywords

As part of a CMS admin, I would like to scan new articles for specific keyphrases/tags that are stored in a mysql db.

I am proficient enough to be able to pull the list of keywords out, loop through them and do stripos, and subst开发者_如何学JAVAr_count to build an array of the found keywords. but the average article is about 700 words and there are 16,000 tags and growing so currently the loop takes about 0.5s which was longer than I had hoped, and will only ever get longer.

Is there a better way of doing this? Even if this type of procedure has a special name, that could help.

I have PHP 5.3 on Fedora, it is also on dedicated servers so I don't have any shared host issues.

EDIT - I am such a scatterbrain, I swore blind that I copy and pasted some code! clearly not

$found = array();
while($row = $pointer->fetch_assoc())
{
    if(stripos($haystack, $row["Name"]) )
    {
        $found[$row["Name"]] = substr_count( $haystack, $row["Name"]);
    }
}
arsort($found);

I think I explained myself badly, because I want to do the procedure on new articles they are currently not in the database, so I was just going to use $_POST in an ajax request, rather than saving the article to the DB first.

http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html is exactly what you are looking for if you don't want to use a search engine script such as sphinx/solr.

It sounds like your code looks something like this:

foreach($keywords as $keyword){
    if(strpos($keyword, $articleText) != -1){
        $foundKeywords[] = $keyword;
    }
}

Something you may consider since the keywords array is so large and will continue to grow is to switch your processing to loop through the words in the text instead of the keywords array. Something like this:

$textWords = explode(" ", $articleText);

foreach($textWords as $word){
    if( array_search($word, $keywords) && !array_search($word, $foundKeywords) ){
        $foundKeywords[] = $word;
    } 
}