How do you get the size of an individual index in MongoDB?

Question

I know I can use db.collection.totalIndexSize() to get the total index size, but I'm interested in seeing the size of an individual index.

Is this supported?

Answer 1

Certainly can. db.collection.stats().indexSizes is an embedded document where each index name is a key and the value is the total index size in bytes :

> db.test.stats() {         "ns" : "test.test",          <snip>         "indexSizes" : {                 "_id_" : 137904592,                 "a_1" : 106925728         },         "ok" : 1 }