I’ve got a bee in my bonnet to figure out a good way to implement a simple tagging scheme like the one used by del.icio.us. My particular question is, is it better to leave the tags in a text field and union them on the fly, or do some sort of pre-processing into an intermediate state before querying them?
Where are you using them? For what? If it's for this site, I'd just punt it and use an existing tags plugin. If it's for something else, well, I dunno, I'd assume for del.icio.us - which is really a tagging app - that tags are central, and probably stored and indexer all on their own. Are you building a tagging app, or adding tagging into an existing app?
Pete,
I'm thinking of adding them to an existing enterprise app. I'm wondering if del.icio.us parses out the tags and adds new records in some separate tag table with a join table mapping urls to tags, or if you could somehow write a query that returned all the space-separated values for a simple text column. then you can just do a 'select * where [text field] like '%tag%'.