Try to fix compilation issue on macOS

src/engine/Server.cpp

@@ -645,7 +645,7 @@ boost::asio::awaitable<void> Server::processQuery(
     } else if (containsParam("action", "binary_export")) {
       mediaType = MediaType::octetStream;
     }
-    std::optional<size_t> maxSend =
+    std::optional<uint64_t> maxSend =
         params.contains("send") ? std::optional{std::stoul(params.at("send"))}
                                 : std::nullopt;
     // Limit JSON requests by default
@@ -827,7 +827,7 @@ Awaitable<T> Server::computeInNewThread(Function function,
 net::awaitable<std::optional<Server::PlannedQuery>> Server::parseAndPlan(
     const std::string& query, QueryExecutionContext& qec,
     SharedCancellationHandle handle, TimeLimit timeLimit,
-    std::optional<size_t> maxSend) {
+    std::optional<uint64_t> maxSend) {
   auto handleCopy = handle;
 
   // The usage of an `optional` here is required because of a limitation in

src/engine/Server.h

@@ -184,7 +184,7 @@ class Server {
   net::awaitable<std::optional<PlannedQuery>> parseAndPlan(
       const std::string& query, QueryExecutionContext& qec,
       SharedCancellationHandle handle, TimeLimit timeLimit,
-      std::optional<size_t> maxSend);
+      std::optional<uint64_t> maxSend);
 
   /// Acquire the `CancellationHandle` for the given `QueryId`, start the
   /// watchdog and call `cancelAfterDeadline` to set the timeout after

src/global/Constants.h

@@ -23,7 +23,7 @@ static const ad_utility::MemorySize STXXL_DISK_SIZE_INDEX_BUILDER = 1_GB;
 
 static constexpr ad_utility::MemorySize DEFAULT_MEM_FOR_QUERIES = 4_GB;
 
-static const size_t MAX_NOF_ROWS_IN_RESULT = 1'000'000;
+constexpr uint64_t MAX_NOF_ROWS_IN_RESULT = 1'000'000;
 static const size_t MIN_WORD_PREFIX_SIZE = 4;
 static const char PREFIX_CHAR = '*';