diff --git a/squangle/logger/DBEventCounter.cpp b/squangle/logger/DBEventCounter.cpp
index d376fc9..13fedc2 100644
--- a/squangle/logger/DBEventCounter.cpp
+++ b/squangle/logger/DBEventCounter.cpp
@@ -16,7 +16,7 @@ namespace facebook {
 namespace db {
 
 void ConnectionContextBase::collectNormalValues(
-    AddNormalValueFunction add) const {
+    const AddNormalValueFunction& add) const {
   add("is_ssl", folly::to<std::string>(isSslConnection));
   add("is_ssl_session_reused", folly::to<std::string>(sslSessionReused));
   if (!sslVersion.empty()) {
@@ -37,7 +37,8 @@ void ConnectionContextBase::collectNormalValues(
   }
 }
 
-void ConnectionContextBase::collectIntValues(AddIntValueFunction add) const {
+void ConnectionContextBase::collectIntValues(
+    const AddIntValueFunction& add) const {
   add("ssl_server_cert_validated", isServerCertValidated ? 1 : 0);
   add("ssl_client_identity_cert", isIdentityClientCert ? 1 : 0);
   if (certCacheSize.has_value()) {
diff --git a/squangle/logger/DBEventCounter.h b/squangle/logger/DBEventCounter.h
index ba98101..75809e6 100644
--- a/squangle/logger/DBEventCounter.h
+++ b/squangle/logger/DBEventCounter.h
@@ -30,8 +30,8 @@ using AddIntValueFunction =
 class ConnectionContextBase {
  public:
   virtual ~ConnectionContextBase() {}
-  virtual void collectNormalValues(AddNormalValueFunction add) const;
-  virtual void collectIntValues(AddIntValueFunction add) const;
+  virtual void collectNormalValues(const AddNormalValueFunction& add) const;
+  virtual void collectIntValues(const AddIntValueFunction& add) const;
   virtual std::unique_ptr<ConnectionContextBase> copy() const {
     return std::make_unique<ConnectionContextBase>(*this);
   }
diff --git a/squangle/mysql_client/AsyncConnectionPool.cpp b/squangle/mysql_client/AsyncConnectionPool.cpp
index 3b8dd84..de91bef 100644
--- a/squangle/mysql_client/AsyncConnectionPool.cpp
+++ b/squangle/mysql_client/AsyncConnectionPool.cpp
@@ -195,7 +195,7 @@ std::ostream& operator<<(std::ostream& os, const PoolOptions& options) {
             << ",pool per instance:" << options.poolPerMysqlInstance() << "}";
 }
 
-std::ostream& operator<<(std::ostream& os, PoolKey key) {
+std::ostream& operator<<(std::ostream& os, const PoolKey& key) {
   return os << "{key:" << key.connKey.getDisplayString()
             << ",options:" << key.connOptions.getDisplayString() << "}";
 }
diff --git a/squangle/mysql_client/DbResult.cpp b/squangle/mysql_client/DbResult.cpp
index bb83b7f..ebce65d 100644
--- a/squangle/mysql_client/DbResult.cpp
+++ b/squangle/mysql_client/DbResult.cpp
@@ -206,7 +206,7 @@ void StreamedQueryResult::setResult(
 }
 
 void StreamedQueryResult::setException(folly::exception_wrapper ex) {
-  exception_wrapper_ = ex;
+  exception_wrapper_ = std::move(ex);
 }
 
 void StreamedQueryResult::freeHandler() {
@@ -215,7 +215,7 @@ void StreamedQueryResult::freeHandler() {
 
 MultiQueryStreamHandler::MultiQueryStreamHandler(
     std::shared_ptr<MultiQueryStreamOperation> op)
-    : operation_(op) {}
+    : operation_(std::move(op)) {}
 
 folly::Optional<StreamedQueryResult> MultiQueryStreamHandler::nextQuery() {
   if (state_ == State::RunQuery) {
diff --git a/squangle/mysql_client/PoolKey.h b/squangle/mysql_client/PoolKey.h
index a2349a3..76c1311 100644
--- a/squangle/mysql_client/PoolKey.h
+++ b/squangle/mysql_client/PoolKey.h
@@ -70,7 +70,7 @@ struct PoolKeyStats {
   size_t connection_limit;
 };
 
-std::ostream& operator<<(std::ostream& os, PoolKey key);
+std::ostream& operator<<(std::ostream& os, const PoolKey& key);
 
 class PoolKeyHash {
  public:
diff --git a/squangle/mysql_client/Query.cpp b/squangle/mysql_client/Query.cpp
index 2afbadf..5271e9c 100644
--- a/squangle/mysql_client/Query.cpp
+++ b/squangle/mysql_client/Query.cpp
@@ -41,15 +41,17 @@ QueryArgument::QueryArgument(folly::fbstring&& val) : value_(std::move(val)) {}
 
 QueryArgument::QueryArgument(double double_val) : value_(double_val) {}
 
-QueryArgument::QueryArgument(std::initializer_list<QueryArgument> list)
+QueryArgument::QueryArgument(const std::initializer_list<QueryArgument>& list)
     : value_(std::vector<QueryArgument>(list.begin(), list.end())) {}
 
 QueryArgument::QueryArgument(std::vector<QueryArgument> arg_list)
-    : value_(std::vector<QueryArgument>(arg_list.begin(), arg_list.end())) {}
+    : value_(std::move(arg_list)) {}
 
 QueryArgument::QueryArgument() : value_(std::vector<ArgPair>()) {}
 
-QueryArgument::QueryArgument(folly::StringPiece param1, QueryArgument param2)
+QueryArgument::QueryArgument(
+    folly::StringPiece param1,
+    const QueryArgument& param2)
     : value_(std::vector<ArgPair>()) {
   getPairs().emplace_back(ArgPair(param1.str(), param2));
 }
@@ -223,7 +225,9 @@ std::vector<ArgPair>& QueryArgument::getPairs() {
 Query::Query(
     const folly::StringPiece query_text,
     std::vector<QueryArgument> params)
-    : query_text_(query_text), unsafe_query_(false), params_(params) {}
+    : query_text_(query_text),
+      unsafe_query_(false),
+      params_(std::move(params)) {}
 
 Query::~Query() {}
 
diff --git a/squangle/mysql_client/Query.h b/squangle/mysql_client/Query.h
index 608b9be..f9e3c22 100644
--- a/squangle/mysql_client/Query.h
+++ b/squangle/mysql_client/Query.h
@@ -423,7 +423,8 @@ class QueryArgument {
       : value_(static_cast<int64_t>(enum_val)) {}
   /* implicit */ QueryArgument(double double_val);
 
-  /* implicit */ QueryArgument(std::initializer_list<QueryArgument> list);
+  /* implicit */ QueryArgument(
+      const std::initializer_list<QueryArgument>& list);
   /* implicit */ QueryArgument(std::vector<QueryArgument> arg_list);
   /* implicit */ QueryArgument(std::tuple<folly::fbstring, folly::fbstring> tup)
       : value_(tup) {}
@@ -488,7 +489,7 @@ class QueryArgument {
 
   // Pair constructors
   QueryArgument();
-  QueryArgument(folly::StringPiece param1, QueryArgument param2);
+  QueryArgument(folly::StringPiece param1, const QueryArgument& param2);
 
   // Since we already have callsites that use dynamic, we are keeping the
   // support, but internally we unpack them.
diff --git a/squangle/mysql_client/SyncMysqlClient.cpp b/squangle/mysql_client/SyncMysqlClient.cpp
index 7371efd..0727f65 100644
--- a/squangle/mysql_client/SyncMysqlClient.cpp
+++ b/squangle/mysql_client/SyncMysqlClient.cpp
@@ -25,7 +25,8 @@ std::shared_ptr<SyncMysqlClient> SyncMysqlClient::defaultClient() {
 std::unique_ptr<Connection> SyncMysqlClient::createConnection(
     ConnectionKey conn_key,
     MYSQL* mysql_conn) {
-  return std::make_unique<SyncConnection>(this, conn_key, mysql_conn);
+  return std::make_unique<SyncConnection>(
+      this, std::move(conn_key), mysql_conn);
 }
 
 SyncConnection::~SyncConnection() {