SERVER-43273 Add UUID support to count and getIndexSpecs in DBClient

27 files changed, 200 insertions, 108 deletions

diff --git a/src/mongo/client/dbclient_base.cpp b/src/mongo/client/dbclient_base.cpp
index 3bc0f1366f6..b91e5d0f32c 100644
--- a/src/mongo/client/dbclient_base.cpp
+++ b/src/mongo/client/dbclient_base.cpp
@@ -320,19 +320,24 @@ bool DBClientBase::runPseudoCommand(StringData db,
 }
 
 unsigned long long DBClientBase::count(
-    const string& myns, const BSONObj& query, int options, int limit, int skip) {
-    BSONObj cmd = _countCmd(myns, query, options, limit, skip);
+    const NamespaceStringOrUUID nsOrUuid, const BSONObj& query, int options, int limit, int skip) {
+    auto dbName = (nsOrUuid.uuid() ? nsOrUuid.dbname() : (*nsOrUuid.nss()).db().toString());
+    BSONObj cmd = _countCmd(nsOrUuid, query, options, limit, skip);
     BSONObj res;
-    if (!runCommand(nsToDatabase(myns), cmd, res, options))
+    if (!runCommand(dbName, cmd, res, options))
         uasserted(11010, string("count fails:") + res.toString());
     return res["n"].numberLong();
 }
 
 BSONObj DBClientBase::_countCmd(
-    const string& myns, const BSONObj& query, int options, int limit, int skip) {
-    NamespaceString ns(myns);
+    const NamespaceStringOrUUID nsOrUuid, const BSONObj& query, int options, int limit, int skip) {
     BSONObjBuilder b;
-    b.append("count", ns.coll());
+    if (nsOrUuid.uuid()) {
+        const auto uuid = *nsOrUuid.uuid();
+        uuid.appendToBuilder(&b, "count");
+    } else {
+        b.append("count", (*nsOrUuid.nss()).coll());
+    }
     b.append("query", query);
     if (limit)
         b.append("limit", limit);
@@ -785,13 +790,24 @@ void DBClientBase::killCursor(const NamespaceString& ns, long long cursorId) {
         OpMsgRequest::fromDBAndBody(ns.db(), KillCursorsRequest(ns, {cursorId}).toBSON()));
 }
 
-list<BSONObj> DBClientBase::getIndexSpecs(const string& ns, int options) {
+list<BSONObj> DBClientBase::getIndexSpecs(const NamespaceStringOrUUID& nsOrUuid, int options) {
     list<BSONObj> specs;
 
-    BSONObj cmd = BSON("listIndexes" << nsToCollectionSubstring(ns) << "cursor" << BSONObj());
+    BSONObjBuilder bob;
+    if (nsOrUuid.nss()) {
+        bob.append("listIndexes", (*nsOrUuid.nss()).coll());
+        bob.append("cursor", BSONObj());
+    } else {
+        const auto uuid = (*nsOrUuid.uuid());
+        uuid.appendToBuilder(&bob, "listIndexes");
+        bob.append("cursor", BSONObj());
+    }
+
+    BSONObj cmd = bob.obj();
+    auto dbName = (nsOrUuid.uuid() ? nsOrUuid.dbname() : (*nsOrUuid.nss()).db().toString());
 
     BSONObj res;
-    if (runCommand(nsToDatabase(ns), cmd, res, options)) {
+    if (runCommand(dbName, cmd, res, options)) {
         BSONObj cursorObj = res["cursor"].Obj();
         BSONObjIterator i(cursorObj["firstBatch"].Obj());
         while (i.more()) {
@@ -801,8 +817,11 @@ list<BSONObj> DBClientBase::getIndexSpecs(const string& ns, int options) {
         const long long id = cursorObj["id"].Long();
 
         if (id != 0) {
-            invariant(ns == cursorObj["ns"].String());
-            unique_ptr<DBClientCursor> cursor = getMore(ns, id, 0, 0);
+            const auto cursorNs = cursorObj["ns"].String();
+            if (nsOrUuid.nss()) {
+                invariant((*nsOrUuid.nss()).toString() == cursorNs);
+            }
+            unique_ptr<DBClientCursor> cursor = getMore(cursorNs, id, 0, 0);
             while (cursor->more()) {
                 specs.push_back(cursor->nextSafe().getOwned());
             }
diff --git a/src/mongo/client/dbclient_base.h b/src/mongo/client/dbclient_base.h
index d4d5bc315e0..194210f8a24 100644
--- a/src/mongo/client/dbclient_base.h
+++ b/src/mongo/client/dbclient_base.h
@@ -351,7 +351,7 @@ public:
     /** count number of objects in collection ns that match the query criteria specified
         throws UserAssertion if database returns an error
     */
-    virtual unsigned long long count(const std::string& ns,
+    virtual unsigned long long count(NamespaceStringOrUUID nsOrUuid,
                                      const BSONObj& query = BSONObj(),
                                      int options = 0,
                                      int limit = 0,
@@ -500,7 +500,8 @@ public:
      */
     virtual void createIndexes(StringData ns, const std::vector<BSONObj>& specs);
 
-    virtual std::list<BSONObj> getIndexSpecs(const std::string& ns, int options = 0);
+    virtual std::list<BSONObj> getIndexSpecs(const NamespaceStringOrUUID& nsOrUuid,
+                                             int options = 0);
 
     virtual void dropIndex(const std::string& ns, BSONObj keys);
     virtual void dropIndex(const std::string& ns, const std::string& indexName);
@@ -687,8 +688,11 @@ protected:
     /** if the element contains a not master error */
     bool isNotMasterErrorString(const BSONElement& e);
 
-    BSONObj _countCmd(
-        const std::string& ns, const BSONObj& query, int options, int limit, int skip);
+    BSONObj _countCmd(const NamespaceStringOrUUID nsOrUuid,
+                      const BSONObj& query,
+                      int options,
+                      int limit,
+                      int skip);
 
     /**
      * Look up the options available on this client.  Caches the answer from
diff --git a/src/mongo/db/cloner.cpp b/src/mongo/db/cloner.cpp
index 514097ecc87..53822544435 100644
--- a/src/mongo/db/cloner.cpp
+++ b/src/mongo/db/cloner.cpp
@@ -467,7 +467,7 @@ bool Cloner::copyCollection(OperationContext* opCtx,
     }
     BSONObj options = optionsBob.obj();
 
-    auto sourceIndexes = _conn->getIndexSpecs(nss.ns(), QueryOption_SlaveOk);
+    auto sourceIndexes = _conn->getIndexSpecs(nss, QueryOption_SlaveOk);
     auto idIndexSpec = getIdIndexSpec(sourceIndexes);
 
     Lock::DBLock dbWrite(opCtx, dbname, MODE_X);
@@ -752,8 +752,7 @@ Status Cloner::copyDb(OperationContext* opCtx,
         Lock::TempRelease tempRelease(opCtx->lockState());
         for (auto&& params : createCollectionParams) {
             const NamespaceString nss(opts.fromDB, params.collectionName);
-            auto indexSpecs =
-                _conn->getIndexSpecs(nss.ns(), opts.slaveOk ? QueryOption_SlaveOk : 0);
+            auto indexSpecs = _conn->getIndexSpecs(nss, opts.slaveOk ? QueryOption_SlaveOk : 0);
 
             collectionIndexSpecs[params.collectionName] = indexSpecs;
 
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 4a9c6adb937..b9d90555d4e 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -1218,7 +1218,7 @@ void State::finalReduce(OperationContext* opCtx, CurOp* curOp) {
     BSONObj prev;
     BSONList all;
 
-    const auto count = _db.count(_config.incLong.ns(), BSONObj(), QueryOption_SlaveOk);
+    const auto count = _db.count(_config.incLong, BSONObj(), QueryOption_SlaveOk);
     ProgressMeterHolder pm;
     {
         stdx::unique_lock<Client> lk(*opCtx->getClient());
diff --git a/src/mongo/db/dbdirectclient.cpp b/src/mongo/db/dbdirectclient.cpp
index d5ce4367612..be41cc3c86a 100644
--- a/src/mongo/db/dbdirectclient.cpp
+++ b/src/mongo/db/dbdirectclient.cpp
@@ -173,14 +173,14 @@ unique_ptr<DBClientCursor> DBDirectClient::query(const NamespaceStringOrUUID& ns
 }
 
 unsigned long long DBDirectClient::count(
-    const string& ns, const BSONObj& query, int options, int limit, int skip) {
+    const NamespaceStringOrUUID nsOrUuid, const BSONObj& query, int options, int limit, int skip) {
     DirectClientScope directClientScope(_opCtx);
-    BSONObj cmdObj = _countCmd(ns, query, options, limit, skip);
+    BSONObj cmdObj = _countCmd(nsOrUuid, query, options, limit, skip);
 
-    NamespaceString nsString(ns);
+    auto dbName = (nsOrUuid.uuid() ? nsOrUuid.dbname() : (*nsOrUuid.nss()).db().toString());
 
     auto result = CommandHelpers::runCommandDirectly(
-        _opCtx, OpMsgRequest::fromDBAndBody(nsString.db(), std::move(cmdObj)));
+        _opCtx, OpMsgRequest::fromDBAndBody(dbName, std::move(cmdObj)));
 
     uassertStatusOK(getStatusFromCommandResult(result));
     return static_cast<unsigned long long>(result["n"].numberLong());
diff --git a/src/mongo/db/dbdirectclient.h b/src/mongo/db/dbdirectclient.h
index c700baf3d8f..544d1801bcf 100644
--- a/src/mongo/db/dbdirectclient.h
+++ b/src/mongo/db/dbdirectclient.h
@@ -81,7 +81,7 @@ public:
 
     virtual void say(Message& toSend, bool isRetry = false, std::string* actualServer = nullptr);
 
-    virtual unsigned long long count(const std::string& ns,
+    virtual unsigned long long count(const NamespaceStringOrUUID nsOrUuid,
                                      const BSONObj& query = BSONObj(),
                                      int options = 0,
                                      int limit = 0,
diff --git a/src/mongo/db/ops/write_ops_document_stream_integration_test.cpp b/src/mongo/db/ops/write_ops_document_stream_integration_test.cpp
index 529cdb20532..4cd0a41a7d7 100644
--- a/src/mongo/db/ops/write_ops_document_stream_integration_test.cpp
+++ b/src/mongo/db/ops/write_ops_document_stream_integration_test.cpp
@@ -46,7 +46,7 @@ TEST(WriteOpsDocSeq, InsertDocStreamWorks) {
 
     NamespaceString ns("test", "doc_seq");
     conn->dropCollection(ns.ns());
-    ASSERT_EQ(conn->count(ns.ns()), 0u);
+    ASSERT_EQ(conn->count(ns), 0u);
 
     OpMsgRequest request;
     request.body = BSON("insert" << ns.coll() << "$db" << ns.db());
@@ -64,7 +64,7 @@ TEST(WriteOpsDocSeq, InsertDocStreamWorks) {
     auto body = reply->getCommandReply();
     ASSERT_OK(getStatusFromCommandResult(body));
     ASSERT_EQ(body["n"].Int(), 5);
-    ASSERT_EQ(conn->count(ns.ns()), 5u);
+    ASSERT_EQ(conn->count(ns), 5u);
 }
 
 }  // namespace mongo
diff --git a/src/mongo/db/pipeline/document_source_out.cpp b/src/mongo/db/pipeline/document_source_out.cpp
index f4b7127a83d..5a94a997515 100644
--- a/src/mongo/db/pipeline/document_source_out.cpp
+++ b/src/mongo/db/pipeline/document_source_out.cpp
@@ -112,7 +112,7 @@ void DocumentSourceOut::initialize() {
     // Save the original collection options and index specs so we can check they didn't change
     // during computation.
     _originalOutOptions = pExpCtx->mongoProcessInterface->getCollectionOptions(outputNs);
-    _originalIndexes = conn->getIndexSpecs(outputNs.ns());
+    _originalIndexes = conn->getIndexSpecs(outputNs);
 
     // Check if it's capped to make sure we have a chance of succeeding before we do all the work.
     // If the collection becomes capped during processing, the collection options will have changed,
diff --git a/src/mongo/db/pipeline/process_interface_standalone.cpp b/src/mongo/db/pipeline/process_interface_standalone.cpp
index b2cf5722c7b..5f7955a2f49 100644
--- a/src/mongo/db/pipeline/process_interface_standalone.cpp
+++ b/src/mongo/db/pipeline/process_interface_standalone.cpp
@@ -359,7 +359,7 @@ void MongoInterfaceStandalone::renameIfOptionsAndIndexesHaveNotChanged(
             SimpleBSONObjComparator::kInstance.evaluate(originalCollectionOptions ==
                                                         getCollectionOptions(targetNs)));
 
-    auto currentIndexes = _client.getIndexSpecs(targetNs.ns());
+    auto currentIndexes = _client.getIndexSpecs(targetNs);
     uassert(ErrorCodes::CommandFailed,
             str::stream() << "indexes of target collection " << targetNs.ns()
                           << " changed during processing.",
diff --git a/src/mongo/db/s/collection_range_deleter_test.cpp b/src/mongo/db/s/collection_range_deleter_test.cpp
index f6f6beb43c6..a14e660bc9a 100644
--- a/src/mongo/db/s/collection_range_deleter_test.cpp
+++ b/src/mongo/db/s/collection_range_deleter_test.cpp
@@ -178,7 +178,7 @@ TEST_F(CollectionRangeDeleterTest, OneDocumentInOneRangeToClean) {
 
     ASSERT_TRUE(dbclient.findOne(kNss.toString(), QUERY(kShardKey << 5)).isEmpty());
     ASSERT_FALSE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 }
 
 // Tests the case that there are multiple documents within a range to clean.
@@ -188,7 +188,7 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInOneRangeToClean) {
     dbclient.insert(kNss.toString(), BSON(kShardKey << 1));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 2));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 3));
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     std::list<Deletion> ranges;
     auto deletion = Deletion{ChunkRange(BSON(kShardKey << 0), BSON(kShardKey << 10)), Date_t{}};
@@ -198,9 +198,9 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInOneRangeToClean) {
 
     ASSERT_TRUE(next(rangeDeleter, 100));
     ASSERT_TRUE(next(rangeDeleter, 100));
-    ASSERT_EQUALS(0ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(0ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
     ASSERT_FALSE(next(rangeDeleter, 100));
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 }
 
 // Tests the case that there are multiple documents within a range to clean, and the range deleter
@@ -211,7 +211,7 @@ TEST_F(CollectionRangeDeleterTest, MultipleCleanupNextRangeCalls) {
     dbclient.insert(kNss.toString(), BSON(kShardKey << 1));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 2));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 3));
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     std::list<Deletion> ranges;
     auto deletion = Deletion{ChunkRange(BSON(kShardKey << 0), BSON(kShardKey << 10)), Date_t{}};
@@ -220,16 +220,16 @@ TEST_F(CollectionRangeDeleterTest, MultipleCleanupNextRangeCalls) {
     ASSERT(when && *when == Date_t{});
 
     ASSERT_TRUE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(2ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(2ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     ASSERT_TRUE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(1ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(1ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     ASSERT_TRUE(next(rangeDeleter, 1));
     ASSERT_TRUE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(0ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(0ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
     ASSERT_FALSE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 }
 
 // Tests the case that there are two ranges to clean, each containing multiple documents.
@@ -242,7 +242,7 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     dbclient.insert(kNss.toString(), BSON(kShardKey << 4));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 5));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 6));
-    ASSERT_EQUALS(6ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 10)));
+    ASSERT_EQUALS(6ULL, dbclient.count(kNss, BSON(kShardKey << LT << 10)));
 
     std::list<Deletion> ranges;
     auto later = Date_t::now();
@@ -284,20 +284,20 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     ASSERT_FALSE(notifn1 != *optNotifn1);
 
     // no op log entry yet
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 
-    ASSERT_EQUALS(6ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 7)));
+    ASSERT_EQUALS(6ULL, dbclient.count(kNss, BSON(kShardKey << LT << 7)));
 
     // catch range3, [3..4) only
     auto next1 = next(rangeDeleter, 100);
     ASSERT_TRUE(next1);
 
     // no op log entry for immediate deletions
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 
     // 3 gone
-    ASSERT_EQUALS(5ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 7)));
-    ASSERT_EQUALS(2ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 4)));
+    ASSERT_EQUALS(5ULL, dbclient.count(kNss, BSON(kShardKey << LT << 7)));
+    ASSERT_EQUALS(2ULL, dbclient.count(kNss, BSON(kShardKey << LT << 4)));
 
     ASSERT_FALSE(notifn1.ready());  // no trigger yet
     ASSERT_FALSE(notifn2.ready());  // no trigger yet
@@ -308,11 +308,11 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     ASSERT_TRUE(next2);
 
     // still no op log entry, because not delayed
-    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(0ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
 
     // deleted 1, 5 left
-    ASSERT_EQUALS(2ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 4)));
-    ASSERT_EQUALS(5ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 10)));
+    ASSERT_EQUALS(2ULL, dbclient.count(kNss, BSON(kShardKey << LT << 4)));
+    ASSERT_EQUALS(5ULL, dbclient.count(kNss, BSON(kShardKey << LT << 10)));
 
     ASSERT_FALSE(notifn1.ready());  // no trigger yet
     ASSERT_FALSE(notifn2.ready());  // no trigger yet
@@ -328,9 +328,9 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     ASSERT_FALSE(notifn2.ready());  // no trigger yet
 
     // deleted 3, 3 left
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 10)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 10)));
 
-    ASSERT_EQUALS(1ULL, dbclient.count(kAdminSysVer.ns(), BSON(kShardKey << "startRangeDeletion")));
+    ASSERT_EQUALS(1ULL, dbclient.count(kAdminSysVer, BSON(kShardKey << "startRangeDeletion")));
     // clang-format off
     ASSERT_BSONOBJ_EQ(
         BSON("_id" << "startRangeDeletion" << "ns" << kNss.ns()
@@ -355,7 +355,7 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     // clang-format on
 
     // still 3 left
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 10)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 10)));
 
     // delete the remaining documents
     auto next5 = next(rangeDeleter, 100);
@@ -372,7 +372,7 @@ TEST_F(CollectionRangeDeleterTest, MultipleDocumentsInMultipleRangesToClean) {
     // clang-format on
 
     // all docs gone
-    ASSERT_EQUALS(0ULL, dbclient.count(kNss.ns(), BSON(kShardKey << LT << 10)));
+    ASSERT_EQUALS(0ULL, dbclient.count(kNss, BSON(kShardKey << LT << 10)));
 
     // discover there are no more, pop range 2
     auto next6 = next(rangeDeleter, 100);
@@ -393,7 +393,7 @@ TEST_F(CollectionRangeDeleterTest, RetryOnWriteConflictException) {
     dbclient.insert(kNss.toString(), BSON(kShardKey << 1));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 2));
     dbclient.insert(kNss.toString(), BSON(kShardKey << 3));
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     std::list<Deletion> ranges;
     auto deletion = Deletion{ChunkRange(BSON(kShardKey << 0), BSON(kShardKey << 10)), Date_t{}};
@@ -405,13 +405,13 @@ TEST_F(CollectionRangeDeleterTest, RetryOnWriteConflictException) {
     rangeDeleter.setDoDeletionShouldThrowWriteConflictForTest(true);
 
     ASSERT_TRUE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(3ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(3ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 
     // TODO SERVER-41606: Remove this function when we refactor CollectionRangeDeleter.
     rangeDeleter.setDoDeletionShouldThrowWriteConflictForTest(false);
 
     ASSERT_TRUE(next(rangeDeleter, 1));
-    ASSERT_EQUALS(2ULL, dbclient.count(kNss.toString(), BSON(kShardKey << LT << 5)));
+    ASSERT_EQUALS(2ULL, dbclient.count(kNss, BSON(kShardKey << LT << 5)));
 }
 
 }  // namespace
diff --git a/src/mongo/db/s/shard_metadata_util_test.cpp b/src/mongo/db/s/shard_metadata_util_test.cpp
index 110cecee0bb..771dbab13ec 100644
--- a/src/mongo/db/s/shard_metadata_util_test.cpp
+++ b/src/mongo/db/s/shard_metadata_util_test.cpp
@@ -129,7 +129,7 @@ struct ShardMetadataUtilTest : public ShardServerTestFixture {
     void checkCollectionIsEmpty(const NamespaceString& nss) {
         try {
             DBDirectClient client(operationContext());
-            ASSERT_EQUALS(client.count(nss.ns()), 0ULL);
+            ASSERT_EQUALS(client.count(nss), 0ULL);
         } catch (const DBException&) {
             ASSERT(false);
         }
diff --git a/src/mongo/db/s/shardsvr_shard_collection.cpp b/src/mongo/db/s/shardsvr_shard_collection.cpp
index af579daa7cd..c3e21103c37 100644
--- a/src/mongo/db/s/shardsvr_shard_collection.cpp
+++ b/src/mongo/db/s/shardsvr_shard_collection.cpp
@@ -219,7 +219,7 @@ void createCollectionOrValidateExisting(OperationContext* opCtx,
     // 5. If the collection is empty, and it's still possible to create an index
     //    on the proposed key, we go ahead and do so.
     DBDirectClient localClient(opCtx);
-    std::list<BSONObj> indexes = localClient.getIndexSpecs(nss.ns());
+    std::list<BSONObj> indexes = localClient.getIndexSpecs(nss);
 
     // 1. Verify consistency with existing unique indexes
     for (const auto& idx : indexes) {
diff --git a/src/mongo/db/s/split_vector_test.cpp b/src/mongo/db/s/split_vector_test.cpp
index 0db74b87b66..22e226ff4ce 100644
--- a/src/mongo/db/s/split_vector_test.cpp
+++ b/src/mongo/db/s/split_vector_test.cpp
@@ -59,7 +59,7 @@ public:
             BSONObj obj = builder.obj();
             dbclient.insert(kNss.toString(), obj);
         }
-        ASSERT_EQUALS(100ULL, dbclient.count(kNss.toString()));
+        ASSERT_EQUALS(100ULL, dbclient.count(kNss));
     }
 
     const long long& getDocSizeBytes() {
@@ -320,7 +320,7 @@ public:
         for (int i = 0; i < 1000; i++) {
             dbclient.insert(kJumboNss.toString(), obj);
         }
-        ASSERT_EQUALS(1000ULL, dbclient.count(kJumboNss.toString()));
+        ASSERT_EQUALS(1000ULL, dbclient.count(kJumboNss));
     }
 
     const long long& getDocSizeBytes() {
@@ -377,7 +377,7 @@ public:
             BSONObj obj = builder.obj();
             dbclient.insert(kMaxResponseNss.toString(), obj);
         }
-        ASSERT_EQUALS(numDocs, (int)dbclient.count(kMaxResponseNss.toString()));
+        ASSERT_EQUALS(numDocs, (int)dbclient.count(kMaxResponseNss));
     }
 
     std::string createUniqueHalfMegabyteString(int uniqueInt) {
diff --git a/src/mongo/db/sessions_collection_rs.cpp b/src/mongo/db/sessions_collection_rs.cpp
index c6aaa9d0a94..316b95b53de 100644
--- a/src/mongo/db/sessions_collection_rs.cpp
+++ b/src/mongo/db/sessions_collection_rs.cpp
@@ -154,7 +154,7 @@ Status SessionsCollectionRS::setupSessionsCollection(OperationContext* opCtx) {
 Status SessionsCollectionRS::checkSessionsCollectionExists(OperationContext* opCtx) {
     DBDirectClient client(opCtx);
 
-    auto indexes = client.getIndexSpecs(NamespaceString::kLogicalSessionsNamespace.toString());
+    auto indexes = client.getIndexSpecs(NamespaceString::kLogicalSessionsNamespace);
 
     if (indexes.size() == 0u) {
         return Status{ErrorCodes::NamespaceNotFound, "config.system.sessions does not exist"};
diff --git a/src/mongo/db/sessions_collection_standalone.cpp b/src/mongo/db/sessions_collection_standalone.cpp
index 764cf9ccaea..2b1f815decc 100644
--- a/src/mongo/db/sessions_collection_standalone.cpp
+++ b/src/mongo/db/sessions_collection_standalone.cpp
@@ -71,7 +71,7 @@ Status SessionsCollectionStandalone::setupSessionsCollection(OperationContext* o
 Status SessionsCollectionStandalone::checkSessionsCollectionExists(OperationContext* opCtx) {
     DBDirectClient client(opCtx);
 
-    auto indexes = client.getIndexSpecs(NamespaceString::kLogicalSessionsNamespace.toString());
+    auto indexes = client.getIndexSpecs(NamespaceString::kLogicalSessionsNamespace);
 
     if (indexes.size() == 0u) {
         return Status{ErrorCodes::NamespaceNotFound, "config.system.sessions does not exist"};
diff --git a/src/mongo/dbtests/clienttests.cpp b/src/mongo/dbtests/clienttests.cpp
index 77d690847cd..a18f4c259b7 100644
--- a/src/mongo/dbtests/clienttests.cpp
+++ b/src/mongo/dbtests/clienttests.cpp
@@ -62,6 +62,10 @@ public:
         db.dropCollection(_ns);
     }
 
+    const NamespaceString nss() {
+        return NamespaceString(_ns);
+    }
+
     const char* ns() {
         return _ns.c_str();
     }
@@ -79,19 +83,19 @@ public:
         DBDirectClient db(&opCtx);
 
         db.insert(ns(), BSON("x" << 2));
-        ASSERT_EQUALS(1u, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(1u, db.getIndexSpecs(nss()).size());
 
         ASSERT_OK(dbtests::createIndex(&opCtx, ns(), BSON("x" << 1)));
-        ASSERT_EQUALS(2u, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(2u, db.getIndexSpecs(nss()).size());
 
         db.dropIndex(ns(), BSON("x" << 1));
-        ASSERT_EQUALS(1u, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(1u, db.getIndexSpecs(nss()).size());
 
         ASSERT_OK(dbtests::createIndex(&opCtx, ns(), BSON("x" << 1)));
-        ASSERT_EQUALS(2u, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(2u, db.getIndexSpecs(nss()).size());
 
         db.dropIndexes(ns());
-        ASSERT_EQUALS(1u, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(1u, db.getIndexSpecs(nss()).size());
     }
 };
 
@@ -118,18 +122,18 @@ public:
 
         ASSERT_EQUALS(1, indexCatalog->numIndexesReady(&opCtx));
         // _id index
-        ASSERT_EQUALS(1U, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(1U, db.getIndexSpecs(nss()).size());
 
         ASSERT_EQUALS(ErrorCodes::DuplicateKey,
                       dbtests::createIndex(&opCtx, ns(), BSON("y" << 1), true));
 
         ASSERT_EQUALS(1, indexCatalog->numIndexesReady(&opCtx));
-        ASSERT_EQUALS(1U, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(1U, db.getIndexSpecs(nss()).size());
 
         ASSERT_OK(dbtests::createIndex(&opCtx, ns(), BSON("x" << 1), true));
 
         ASSERT_EQUALS(2, indexCatalog->numIndexesReady(&opCtx));
-        ASSERT_EQUALS(2U, db.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(2U, db.getIndexSpecs(nss()).size());
     }
 };
 
diff --git a/src/mongo/dbtests/commandtests.cpp b/src/mongo/dbtests/commandtests.cpp
index 2a464621bcd..efce5cb65e3 100644
--- a/src/mongo/dbtests/commandtests.cpp
+++ b/src/mongo/dbtests/commandtests.cpp
@@ -50,7 +50,7 @@ TEST(CommandTests, InputDocumentSequeceWorksEndToEnd) {
     NamespaceString nss("test", "doc_seq");
     DBDirectClient db(opCtx);
     db.dropCollection(nss.ns());
-    ASSERT_EQ(db.count(nss.ns()), 0u);
+    ASSERT_EQ(db.count(nss), 0u);
 
     OpMsgRequest request;
     request.body = BSON("insert" << nss.coll() << "$db" << nss.db());
@@ -66,7 +66,7 @@ TEST(CommandTests, InputDocumentSequeceWorksEndToEnd) {
     const auto reply = db.runCommand(std::move(request));
     ASSERT_EQ(int(reply->getProtocol()), int(rpc::Protocol::kOpMsg));
     ASSERT_BSONOBJ_EQ(reply->getCommandReply(), BSON("n" << 5 << "ok" << 1.0));
-    ASSERT_EQ(db.count(nss.ns()), 5u);
+    ASSERT_EQ(db.count(nss), 5u);
 }
 
 using std::string;
diff --git a/src/mongo/dbtests/counttests.cpp b/src/mongo/dbtests/counttests.cpp
index 86f3ac51b71..9329f88245f 100644
--- a/src/mongo/dbtests/counttests.cpp
+++ b/src/mongo/dbtests/counttests.cpp
@@ -123,7 +123,7 @@ public:
     void run() {
         insert("{\"a\":\"b\"}");
         insert("{\"c\":\"d\"}");
-        ASSERT_EQUALS(2ULL, _client.count(ns(), fromjson("{}")));
+        ASSERT_EQUALS(2ULL, _client.count(nss(), fromjson("{}")));
     }
 };
 
@@ -133,7 +133,7 @@ public:
         insert("{\"a\":\"b\"}");
         insert("{\"a\":\"b\",\"x\":\"y\"}");
         insert("{\"a\":\"c\"}");
-        ASSERT_EQUALS(2ULL, _client.count(ns(), fromjson("{\"a\":\"b\"}")));
+        ASSERT_EQUALS(2ULL, _client.count(nss(), fromjson("{\"a\":\"b\"}")));
     }
 };
 
@@ -143,7 +143,7 @@ public:
         insert("{\"a\":\"b\"}");
         insert("{\"a\":\"c\"}");
         insert("{\"d\":\"e\"}");
-        ASSERT_EQUALS(1ULL, _client.count(ns(), fromjson("{\"a\":\"b\"}")));
+        ASSERT_EQUALS(1ULL, _client.count(nss(), fromjson("{\"a\":\"b\"}")));
     }
 };
 
@@ -153,7 +153,7 @@ public:
         insert("{\"a\":\"c\"}");
         insert("{\"a\":\"b\"}");
         insert("{\"a\":\"d\"}");
-        ASSERT_EQUALS(1ULL, _client.count(ns(), fromjson("{\"a\":/^b/}")));
+        ASSERT_EQUALS(1ULL, _client.count(nss(), fromjson("{\"a\":/^b/}")));
     }
 };
 
diff --git a/src/mongo/dbtests/directclienttests.cpp b/src/mongo/dbtests/directclienttests.cpp
index c1b80628851..5b120ee484e 100644
--- a/src/mongo/dbtests/directclienttests.cpp
+++ b/src/mongo/dbtests/directclienttests.cpp
@@ -105,12 +105,12 @@ public:
         client.dropCollection(ns);
         client.insert(ns, objs);
         ASSERT_EQUALS(client.getLastErrorDetailed()["code"].numberInt(), 11000);
-        ASSERT_EQUALS((int)client.count(ns), 1);
+        ASSERT_EQUALS((int)client.count(NamespaceString(ns)), 1);
 
         client.dropCollection(ns);
         client.insert(ns, objs, InsertOption_ContinueOnError);
         ASSERT_EQUALS(client.getLastErrorDetailed()["code"].numberInt(), 11000);
-        ASSERT_EQUALS((int)client.count(ns), 2);
+        ASSERT_EQUALS((int)client.count(NamespaceString(ns)), 2);
     }
 };
 
diff --git a/src/mongo/dbtests/indexupdatetests.cpp b/src/mongo/dbtests/indexupdatetests.cpp
index 6ceebc55c1b..244b2088119 100644
--- a/src/mongo/dbtests/indexupdatetests.cpp
+++ b/src/mongo/dbtests/indexupdatetests.cpp
@@ -532,7 +532,7 @@ public:
         client.insert(_ns, BSON("a" << BSONSymbol("mySymbol")));
         ASSERT_EQUALS(client.getLastErrorDetailed()["code"].numberInt(),
                       ErrorCodes::CannotBuildIndexKeys);
-        ASSERT_EQUALS(client.count(_ns), 0U);
+        ASSERT_EQUALS(client.count(_nss), 0U);
     }
 };
 
@@ -547,7 +547,7 @@ public:
         client.createIndex(_ns, indexSpec);
         client.insert(_ns, BSON("a" << BSONSymbol("mySymbol")));
         ASSERT(client.getLastError().empty());
-        ASSERT_EQUALS(client.count(_ns), 1U);
+        ASSERT_EQUALS(client.count(_nss), 1U);
     }
 };
 
@@ -564,7 +564,7 @@ public:
         client.insert(_ns, BSON("a" << BSON("b" << 99 << "c" << BSONSymbol("mySymbol"))));
         ASSERT_EQUALS(client.getLastErrorDetailed()["code"].numberInt(),
                       ErrorCodes::CannotBuildIndexKeys);
-        ASSERT_EQUALS(client.count(_ns), 0U);
+        ASSERT_EQUALS(client.count(_nss), 0U);
     }
 };
 
@@ -581,7 +581,7 @@ public:
         client.insert(_ns, BSON("a" << BSON_ARRAY(99 << BSONSymbol("mySymbol"))));
         ASSERT_EQUALS(client.getLastErrorDetailed()["code"].numberInt(),
                       ErrorCodes::CannotBuildIndexKeys);
-        ASSERT_EQUALS(client.count(_ns), 0U);
+        ASSERT_EQUALS(client.count(_nss), 0U);
     }
 };
 
@@ -592,7 +592,7 @@ public:
         DBDirectClient client(opCtx.get());
         client.dropCollection(_ns);
         client.insert(_ns, BSON("a" << BSON_ARRAY(99 << BSONSymbol("mySymbol"))));
-        ASSERT_EQUALS(client.count(_ns), 1U);
+        ASSERT_EQUALS(client.count(_nss), 1U);
         IndexSpec indexSpec;
         indexSpec.addKey("a").addOptions(BSON("collation" << BSON("locale"
                                                                   << "fr")));
diff --git a/src/mongo/dbtests/logical_sessions_tests.cpp b/src/mongo/dbtests/logical_sessions_tests.cpp
index 13d3cb75e14..94b0123afce 100644
--- a/src/mongo/dbtests/logical_sessions_tests.cpp
+++ b/src/mongo/dbtests/logical_sessions_tests.cpp
@@ -199,7 +199,7 @@ public:
         ASSERT(resRefresh.isOK());
 
         // Ensure that the right number of timestamps were updated.
-        auto n = db.count(ns(), BSON("lastUse" << now));
+        auto n = db.count(NamespaceString(ns()), BSON("lastUse" << now));
         ASSERT_EQ(n, notRefreshed);
     }
 };
diff --git a/src/mongo/dbtests/query_stage_update.cpp b/src/mongo/dbtests/query_stage_update.cpp
index c0dc47528e4..d83b8479033 100644
--- a/src/mongo/dbtests/query_stage_update.cpp
+++ b/src/mongo/dbtests/query_stage_update.cpp
@@ -94,7 +94,7 @@ public:
     }
 
     size_t count(const BSONObj& query) {
-        return _client.count(nss.ns(), query, 0, 0, 0);
+        return _client.count(nss, query, 0, 0, 0);
     }
 
     unique_ptr<CanonicalQuery> canonicalize(const BSONObj& query) {
diff --git a/src/mongo/dbtests/querytests.cpp b/src/mongo/dbtests/querytests.cpp
index ba0a9eac64d..24bbc5be371 100644
--- a/src/mongo/dbtests/querytests.cpp
+++ b/src/mongo/dbtests/querytests.cpp
@@ -809,7 +809,8 @@ public:
 
 private:
     void count(unsigned long long c) {
-        ASSERT_EQUALS(c, _client.count("unittests.querytests.BasicCount", BSON("a" << 4)));
+        ASSERT_EQUALS(
+            c, _client.count(NamespaceString("unittests.querytests.BasicCount"), BSON("a" << 4)));
     }
 };
 
@@ -904,11 +905,14 @@ public:
     static const char* ns() {
         return "unittests.querytests.AutoResetIndexCache";
     }
+    static const NamespaceString nss() {
+        return NamespaceString(ns());
+    }
     void index() {
-        ASSERT_EQUALS(2u, _client.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(2u, _client.getIndexSpecs(nss()).size());
     }
     void noIndex() {
-        ASSERT_EQUALS(0u, _client.getIndexSpecs(ns()).size());
+        ASSERT_EQUALS(0u, _client.getIndexSpecs(nss()).size());
     }
     void checkIndex() {
         ASSERT_OK(dbtests::createIndex(&_opCtx, ns(), BSON("a" << 1)));
@@ -934,15 +938,16 @@ public:
     }
     void run() {
         const char* ns = "unittests.querytests.UniqueIndex";
+        const NamespaceString nss = NamespaceString(ns);
         ASSERT_OK(dbtests::createIndex(&_opCtx, ns, BSON("a" << 1), true));
         _client.insert(ns, BSON("a" << 4 << "b" << 2));
         _client.insert(ns, BSON("a" << 4 << "b" << 3));
-        ASSERT_EQUALS(1U, _client.count(ns, BSONObj()));
+        ASSERT_EQUALS(1U, _client.count(nss, BSONObj()));
         _client.dropCollection(ns);
         ASSERT_OK(dbtests::createIndex(&_opCtx, ns, BSON("b" << 1), true));
         _client.insert(ns, BSON("a" << 4 << "b" << 2));
         _client.insert(ns, BSON("a" << 4 << "b" << 3));
-        ASSERT_EQUALS(2U, _client.count(ns, BSONObj()));
+        ASSERT_EQUALS(2U, _client.count(nss, BSONObj()));
     }
 };
 
@@ -1129,7 +1134,7 @@ BSONObj MinMax::empty_;
 
 class MatchCodeCodeWScope : public ClientBase {
 public:
-    MatchCodeCodeWScope() : _ns("unittests.querytests.MatchCodeCodeWScope") {}
+    MatchCodeCodeWScope() : _ns("unittests.querytests.MatchCodeCodeWScope"), _nss(_ns) {}
     ~MatchCodeCodeWScope() {
         _client.dropCollection("unittests.querytests.MatchCodeCodeWScope");
     }
@@ -1146,11 +1151,11 @@ private:
         _client.insert(_ns, code());
         _client.insert(_ns, codeWScope());
 
-        ASSERT_EQUALS(1U, _client.count(_ns, code()));
-        ASSERT_EQUALS(1U, _client.count(_ns, codeWScope()));
+        ASSERT_EQUALS(1U, _client.count(_nss, code()));
+        ASSERT_EQUALS(1U, _client.count(_nss, codeWScope()));
 
-        ASSERT_EQUALS(1U, _client.count(_ns, BSON("a" << BSON("$type" << (int)Code))));
-        ASSERT_EQUALS(1U, _client.count(_ns, BSON("a" << BSON("$type" << (int)CodeWScope))));
+        ASSERT_EQUALS(1U, _client.count(_nss, BSON("a" << BSON("$type" << (int)Code))));
+        ASSERT_EQUALS(1U, _client.count(_nss, BSON("a" << BSON("$type" << (int)CodeWScope))));
     }
     BSONObj code() const {
         BSONObjBuilder codeBuilder;
@@ -1163,11 +1168,12 @@ private:
         return codeWScopeBuilder.obj();
     }
     const char* _ns;
+    const NamespaceString _nss;
 };
 
 class MatchDBRefType : public ClientBase {
 public:
-    MatchDBRefType() : _ns("unittests.querytests.MatchDBRefType") {}
+    MatchDBRefType() : _ns("unittests.querytests.MatchDBRefType"), _nss(_ns) {}
     ~MatchDBRefType() {
         _client.dropCollection("unittests.querytests.MatchDBRefType");
     }
@@ -1181,8 +1187,8 @@ private:
     void checkMatch() {
         _client.remove(_ns, BSONObj());
         _client.insert(_ns, dbref());
-        ASSERT_EQUALS(1U, _client.count(_ns, dbref()));
-        ASSERT_EQUALS(1U, _client.count(_ns, BSON("a" << BSON("$type" << (int)DBRef))));
+        ASSERT_EQUALS(1U, _client.count(_nss, dbref()));
+        ASSERT_EQUALS(1U, _client.count(_nss, BSON("a" << BSON("$type" << (int)DBRef))));
     }
     BSONObj dbref() const {
         BSONObjBuilder b;
@@ -1191,6 +1197,7 @@ private:
         return b.obj();
     }
     const char* _ns;
+    const NamespaceString _nss;
 };
 
 class DirectLocking : public ClientBase {
@@ -1215,7 +1222,7 @@ public:
                        BSON("i"
                             << "a"));
         ASSERT_OK(dbtests::createIndex(&_opCtx, ns, BSON("i" << 1)));
-        ASSERT_EQUALS(1U, _client.count(ns, fromjson("{i:{$in:['a']}}")));
+        ASSERT_EQUALS(1U, _client.count(NamespaceString(ns), fromjson("{i:{$in:['a']}}")));
     }
 };
 
@@ -1231,11 +1238,11 @@ public:
         _client.insert(ns, fromjson("{bar:['spam']}"));
         _client.insert(ns, fromjson("{bar:['spam','eggs']}"));
         ASSERT_EQUALS(2U,
-                      _client.count(ns,
+                      _client.count(NamespaceString(ns),
                                     BSON("bar"
                                          << "spam")));
         ASSERT_EQUALS(2U,
-                      _client.count(ns,
+                      _client.count(NamespaceString(ns),
                                     BSON("foo.bar"
                                          << "spam")));
     }
@@ -1305,7 +1312,7 @@ public:
     }
 
     int count() {
-        return (int)_client.count(ns());
+        return (int)_client.count(nss());
     }
 
     size_t numCursorsOpen() {
@@ -1756,6 +1763,63 @@ public:
     }
 };
 
+class CountByUUID : public CollectionBase {
+public:
+    CountByUUID() : CollectionBase("CountByUUID") {}
+
+    void run() {
+        CollectionOptions coll_opts;
+        coll_opts.uuid = UUID::gen();
+        {
+            Lock::GlobalWrite lk(&_opCtx);
+            OldClientContext context(&_opCtx, ns());
+            WriteUnitOfWork wunit(&_opCtx);
+            context.db()->createCollection(&_opCtx, nss(), coll_opts, false);
+            wunit.commit();
+        }
+        insert(ns(), BSON("a" << 1));
+
+        auto count = _client.count(NamespaceStringOrUUID("unittests", *coll_opts.uuid), BSONObj());
+        ASSERT_EQUALS(1U, count);
+
+        insert(ns(), BSON("a" << 2));
+        insert(ns(), BSON("a" << 3));
+
+        count = _client.count(NamespaceStringOrUUID("unittests", *coll_opts.uuid), BSONObj());
+        ASSERT_EQUALS(3U, count);
+    }
+};
+
+class GetIndexSpecsByUUID : public CollectionBase {
+public:
+    GetIndexSpecsByUUID() : CollectionBase("GetIndexSpecsByUUID") {}
+
+    void run() {
+        CollectionOptions coll_opts;
+        coll_opts.uuid = UUID::gen();
+        {
+            Lock::GlobalWrite lk(&_opCtx);
+            OldClientContext context(&_opCtx, ns());
+            WriteUnitOfWork wunit(&_opCtx);
+            context.db()->createCollection(&_opCtx, nss(), coll_opts, true);
+            wunit.commit();
+        }
+        insert(ns(), BSON("a" << 1));
+        insert(ns(), BSON("a" << 2));
+        insert(ns(), BSON("a" << 3));
+
+        auto specsWithIdIndexOnly =
+            _client.getIndexSpecs(NamespaceStringOrUUID(nss().db().toString(), *coll_opts.uuid));
+        ASSERT_EQUALS(1U, specsWithIdIndexOnly.size());
+
+        ASSERT_OK(dbtests::createIndex(&_opCtx, ns(), BSON("a" << 1), true));
+
+        auto specsWithBothIndexes =
+            _client.getIndexSpecs(NamespaceStringOrUUID(nss().db().toString(), *coll_opts.uuid));
+        ASSERT_EQUALS(2U, specsWithBothIndexes.size());
+    }
+};
+
 class CollectionInternalBase : public CollectionBase {
 public:
     CollectionInternalBase(const char* nsLeaf)
@@ -1918,6 +1982,7 @@ public:
         add<FindingStartStale>();
         add<WhatsMyUri>();
         add<QueryByUuid>();
+        add<GetIndexSpecsByUUID>();
         add<Exhaust>();
         add<QueryReadsAll>();
         add<queryobjecttests::names1>();
diff --git a/src/mongo/dbtests/repltests.cpp b/src/mongo/dbtests/repltests.cpp
index 591eafe50e5..f68017aaefb 100644
--- a/src/mongo/dbtests/repltests.cpp
+++ b/src/mongo/dbtests/repltests.cpp
@@ -1321,13 +1321,13 @@ public:
         insert(BSON("_id" << 1 << "a" << 11));
         insert(BSON("_id" << 3 << "a" << 10));
         _client.remove(ns(), BSON("a" << 10));
-        ASSERT_EQUALS(1U, _client.count(ns(), BSONObj()));
+        ASSERT_EQUALS(1U, _client.count(nss(), BSONObj()));
         insert(BSON("_id" << 0 << "a" << 11));
         insert(BSON("_id" << 2 << "a" << 10));
         insert(BSON("_id" << 3 << "a" << 10));
 
         applyAllOperations();
-        ASSERT_EQUALS(2U, _client.count(ns(), BSONObj()));
+        ASSERT_EQUALS(2U, _client.count(nss(), BSONObj()));
         ASSERT(!one(BSON("_id" << 1)).isEmpty());
         ASSERT(!one(BSON("_id" << 2)).isEmpty());
     }
diff --git a/src/mongo/executor/task_executor_cursor_integration_test.cpp b/src/mongo/executor/task_executor_cursor_integration_test.cpp
index 55b75650083..f5ad9b62397 100644
--- a/src/mongo/executor/task_executor_cursor_integration_test.cpp
+++ b/src/mongo/executor/task_executor_cursor_integration_test.cpp
@@ -32,6 +32,7 @@
 #include "mongo/executor/task_executor_cursor.h"
 
 #include "mongo/client/dbclient_base.h"
+#include "mongo/db/namespace_string.h"
 #include "mongo/executor/network_interface_factory.h"
 #include "mongo/executor/network_interface_thread_pool.h"
 #include "mongo/executor/thread_pool_task_executor.h"
@@ -84,7 +85,7 @@ TEST_F(TaskExecutorCursorFixture, Basic) {
     }
     dbclient->dropCollection("test.test");
     dbclient->insert("test.test", docs);
-    ASSERT_EQUALS(dbclient->count("test.test"), numDocs);
+    ASSERT_EQUALS(dbclient->count(NamespaceString("test.test")), numDocs);
 
     RemoteCommandRequest rcr(unittest::getFixtureConnectionString().getServers().front(),
                              "test",
diff --git a/src/mongo/rpc/op_msg_integration_test.cpp b/src/mongo/rpc/op_msg_integration_test.cpp
index 5cd98239b5f..8cfbf1fa6bf 100644
--- a/src/mongo/rpc/op_msg_integration_test.cpp
+++ b/src/mongo/rpc/op_msg_integration_test.cpp
@@ -84,7 +84,7 @@ TEST(OpMsg, FireAndForgetInsertWorks) {
         ]
     })")));
 
-    ASSERT_EQ(conn->count("test.collection"), 1u);
+    ASSERT_EQ(conn->count(NamespaceString("test.collection")), 1u);
 }
 
 TEST(OpMsg, DocumentSequenceLargeDocumentMultiInsertWorks) {
@@ -117,7 +117,7 @@ TEST(OpMsg, DocumentSequenceLargeDocumentMultiInsertWorks) {
     Message reply;
     ASSERT_TRUE(conn->call(request, reply, false));
 
-    ASSERT_EQ(conn->count("test.collection"), 3u);
+    ASSERT_EQ(conn->count(NamespaceString("test.collection")), 3u);
     conn->dropCollection("test.collection");
 }
 
@@ -153,7 +153,7 @@ TEST(OpMsg, DocumentSequenceMaxWriteBatchWorks) {
     Message reply;
     ASSERT_TRUE(conn->call(request, reply, false));
 
-    ASSERT_EQ(conn->count("test.collection"), write_ops::kMaxWriteBatchSize);
+    ASSERT_EQ(conn->count(NamespaceString("test.collection")), write_ops::kMaxWriteBatchSize);
     conn->dropCollection("test.collection");
 }
 
@@ -407,7 +407,7 @@ TEST(OpMsg, ExhaustWithDBClientCursorBehavesCorrectly) {
         conn->insert(nss.toString(), doc, 0);
     }
 
-    ASSERT_EQ(conn->count(nss.toString()), size_t(nDocs));
+    ASSERT_EQ(conn->count(nss), size_t(nDocs));
     unittest::log() << "Finished document insertion.";
 
     // Open an exhaust cursor.
diff --git a/src/mongo/s/commands/cluster_map_reduce.cpp b/src/mongo/s/commands/cluster_map_reduce.cpp
index 6116311f582..59b6e1680ae 100644
--- a/src/mongo/s/commands/cluster_map_reduce.cpp
+++ b/src/mongo/s/commands/cluster_map_reduce.cpp
@@ -533,7 +533,7 @@ bool runMapReduce(OperationContext* opCtx,
                 // collection is empty in order to decide whether we should drop and re-shard
                 // it.
                 // We don't want to do this if the collection is not empty.
-                shouldDropAndShard = (conn->count(outputCollNss.ns()) == 0);
+                shouldDropAndShard = (conn->count(outputCollNss) == 0);
             }
 
             conn.done();