The Index You’ve Added is Useless. Why?

Recently, at the office: Bob: I've looked into that slow query you've told me about yesterday, Alice. I've added the indexes you wanted. Everything should be fine now Alice: Thanks Bob. I'll quickly check ... Nope Bob, still slow, it didn't seem to work Bob: You're right Alice! It looks like Oracle isn't picking up … Continue reading The Index You’ve Added is Useless. Why?