Managing indexes are easy with mongosh.
Show indexes:
db.dtls.getIndexes()
[ { v: 2, key: { _id: 1 }, name: '_id_' } ]
Create a new index:
db.dtls.createIndex({userid: 1})
userid_1
Show indexes:
test> db.dtls.getIndexes()
[
{ v: 2, key: { _id: 1 }, name: '_id_' },
{ v: 2, key: { userid: 1 }, name: 'userid_1' }
]
Remove an index:
test> db.dtls.dropIndex("userid_1")
{ nIndexesWas: 2, ok: 1 }