MongoDB shell version v4.4.8
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("0797f9e4-8be2-4763-ae22-56d664c090e5") }
MongoDB server version: 4.4.8

Searching node for any documents that violate a unique index...

Scanning through 1 collection(s) in database admin.
Scanning collection system.version
Finding unique indexes...
Collection system.version doesn't have any unique indexes. Skipping collection...

Scanning through 1 collection(s) in database config.
Scanning collection system.sessions
Finding unique indexes...
Collection system.sessions doesn't have any unique indexes. Skipping collection...

Scanning through 1 collection(s) in database local.
Scanning collection startup_log
Finding unique indexes...
Collection startup_log doesn't have any unique indexes. Skipping collection...

Scanning through 1 collection(s) in database test.
Scanning collection c
Finding unique indexes...
Searching for duplicates in 1 unique index(es).
Found 4 document(s) with duplicate values.

Found 4 documents that violate a unique index, affecting 1 unique index(es) in 1 collection(s) in 1 database(s).

Results:
[
	{
		"database" : "test",
		"collection" : "c",
		"key" : {
			"t" : 99,
			"i" : 99
		},
		"docs" : [
			{
				"_id" : ObjectId("610425674cd0a4f976c591c3")
			},
			{
				"_id" : ObjectId("6104256a4cd0a4f976c5dc49")
			},
			{
				"_id" : ObjectId("6104256b4cd0a4f976c60294")
			},
			{
				"_id" : ObjectId("6104256c4cd0a4f976c62aae")
			}
		]
	}
]