How many database indexes is too many?

Question

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

Answer 1

What it really comes down to is, don't add an index unless you know (and this often means gathering usage statistics) that it will be used far more often than it's updated.

Any index that doesn't meet that criteria will cost you more to rebuild than the performance penalty of not having it in the odd case it got used.