Eitan Blumin deals with a clone problem:
This article published by Brent Ozar is very informative about redundant/duplicate indexes, what they mean, why they’re bad, and what should be done with them.
Also, a few years ago, Guy Glantser published a post about dropping redundant indexes. It’s very useful for finding all redundant indexes within all tables in a specific database.
But what both of these articles are missing – is the ability to easily generate Drop/Disable commands for these redundant indexes.
Additionally, what if there are “similar” indexes that are only “partially” redundant, and therefore it’s not enough to simply drop one of them? Otherwise, some queries may suffer a negative performance impact.
Click through for the article and be sure to pay close attention to the important note, which I’ll summarize: “kind of redundant” doesn’t always mean redundant.