Question

what do you think would be performance-wise the better way to get the category-names of a news-system:

1. add an extra field for the cat-names inside a table, which allreade contains a field for the cat-ids

2. no extra field for the cat-names, but cat-ids and read in the cat-names (comma-seperated string: “cat1,cat2,cat3,cat4”) into the php-file by an existing config-file and then build the cat-names with the help of the db-field “cat-ids” an array and a for-loop?

Thanx in advance,

Jayden

edit: cant seem to add a “hi” or “hallo” on top of the post, the editor just deletes it…

Answer 1

If you are measuring milliseconds and the disk IO of your system is not extremely slow, then option 2 would yield better performance. But, we are talking a negligible gain in execution time. Since you already will be querying the DB to get the news item it would be highly optimized to just get the category name at the same time. I would add a mapping table of category-name-id to category-names. And the join on that when getting news items.

From a flexibility standpoint and the standpoint of eliminating as many possible sources of error I would also go with my above idea. Since it adds flexibility to your system and keeps all your data in one spot. Changing the name of a category would require editing one column i the database instead of editing a php config file or, if option 1 was used, updating each and every news record.

So my best advise, add a table with category-name-id to category-names mappings and then have the news-items contain the id of the category they belong to.

For performance you could then cache the data you retrieve about existing categories and other data so you don’t have to poll the DB for that information all the time.

For instance. You could, instead of joining at all, get all the categories from the category table I described above. Cache it in the application and only get it once the cache is invalidated. i.e. a timeout occurs or the data in the db is manipulated.