I\'m working on a project with a rather large Oracle database (although my question applies equally well to other databases). We have a web interface which allows users to
If you do mostly reads (and few updates) then there's really no reason not to index everything you'll need to index. If you update often, then you may need to be cautious on how many indexes you have. There's no hard number, but you'll notice when things start to slow down. Make sure your clustered index is the one that makes the most sense based on the data.