diff --git a/src/util/Error.h b/src/util/Error.h
index d4bf22e7a..c95ec76b0 100644
--- a/src/util/Error.h
+++ b/src/util/Error.h
@@ -60,7 +60,9 @@ struct ErrorCode {
         CREATE_TABLE,
         MYSQLCONNECT,
         MYSQLEXEC,
-        INTERNAL
+        INTERNAL,
+        // Worker errors:
+        WORKER_RESULT_TOO_LARGE
     };
 };
 
diff --git a/src/util/MultiError.cc b/src/util/MultiError.cc
index da0723c41..bf1ac1361 100644
--- a/src/util/MultiError.cc
+++ b/src/util/MultiError.cc
@@ -52,6 +52,8 @@ std::string MultiError::toOneLineString() const {
     return oss.str();
 }
 
+int MultiError::firstErrorCode() const { return empty() ? ErrorCode::NONE : _errorVector.front().getCode(); }
+
 bool MultiError::empty() const { return _errorVector.empty(); }
 
 std::vector<Error>::size_type MultiError::size() const { return _errorVector.size(); }
diff --git a/src/util/MultiError.h b/src/util/MultiError.h
index 678b7171a..ea0d62048 100644
--- a/src/util/MultiError.h
+++ b/src/util/MultiError.h
@@ -69,6 +69,15 @@ class MultiError : public std::exception {
      */
     std::string toOneLineString() const;
 
+    /** Return the first error code (if any)
+     *
+     * The idea is to return the first code that might trigger the "chain" reaction.
+     * An interpretation of the code depns on a context.
+     *
+     * @return the code or ErrorCode::NONE if the collection of errors is empty
+     */
+    int firstErrorCode() const;
+
     virtual ~MultiError() throw() {}
 
     /** Overload output operator for this class
diff --git a/src/wbase/FileChannelShared.cc b/src/wbase/FileChannelShared.cc
index 6b3e23ee6..2254c705d 100644
--- a/src/wbase/FileChannelShared.cc
+++ b/src/wbase/FileChannelShared.cc
@@ -216,7 +216,7 @@ bool FileChannelShared::buildAndTransmitResult(MYSQL_RES* mResult, shared_ptr<Ta
     transmitT.start();
 
     double bufferFillSecs = 0.0;
-    int bytesTransmitted = 0;
+    int64_t bytesTransmitted = 0;
     int rowsTransmitted = 0;
 
     // Keep reading rows and converting those into messages while any
@@ -259,6 +259,19 @@ bool FileChannelShared::buildAndTransmitResult(MYSQL_RES* mResult, shared_ptr<Ta
         _rowcount += rows;
         _transmitsize += bytes;
 
+        // Fail the operation if the amount of data in the result set exceeds the requested
+        // "large result" limit (in case if the one was specified).
+        if (int64_t const maxTableSize = task->getMaxTableSize();
+            maxTableSize > 0 && bytesTransmitted > maxTableSize) {
+            string const err = "The result set size " + to_string(bytesTransmitted) +
+                               " of a job exceeds the requested limit of " + to_string(maxTableSize) +
+                               " bytes, task: " + task->getIdStr();
+            multiErr.push_back(util::Error(util::ErrorCode::WORKER_RESULT_TOO_LARGE, err));
+            LOGS(_log, LOG_LVL_ERROR, err);
+            erred = true;
+            break;
+        }
+
         // If no more rows are left in the task's result set then we need to check
         // if this is last task in a logical group of ones created for processing
         // the current request (note that certain classes of requests may require
diff --git a/src/wbase/Task.cc b/src/wbase/Task.cc
index 1871c67b2..1bca050aa 100644
--- a/src/wbase/Task.cc
+++ b/src/wbase/Task.cc
@@ -89,6 +89,9 @@ string buildResultFilePath(shared_ptr<lsst::qserv::proto::TaskMsg> const& taskMs
             to_string(taskMsg->chunkid()) + "-" + to_string(taskMsg->attemptcount()) + ".proto";
     return path.string();
 }
+
+size_t const MB_SIZE_BYTES = 1024 * 1024;
+
 }  // namespace
 
 namespace lsst::qserv::wbase {
@@ -184,6 +187,7 @@ Task::Task(TaskMsgPtr const& t, int fragmentNumber, std::shared_ptr<UserQueryInf
     _scanInfo.scanRating = t->scanpriority();
     _scanInfo.sortTablesSlowestFirst();
     _scanInteractive = t->scaninteractive();
+    _maxTableSize = t->maxtablesize_mb() * ::MB_SIZE_BYTES;
 
     // Create sets and vectors for 'aquiring' subchunk temporary tables.
     proto::TaskMsg_Fragment const& fragment(t->fragment(_queryFragmentNum));
@@ -473,6 +477,7 @@ nlohmann::json Task::getJson() const {
     js["attemptId"] = _attemptCount;
     js["sequenceId"] = _tSeq;
     js["scanInteractive"] = _scanInteractive;
+    js["maxTableSize"] = _maxTableSize;
     js["cancelled"] = to_string(_cancelled);
     js["state"] = static_cast<uint64_t>(_state.load());
     js["createTime_msec"] = util::TimeUtils::tp2ms(_createTime);
diff --git a/src/wbase/Task.h b/src/wbase/Task.h
index eba22bcdd..f68d6622a 100644
--- a/src/wbase/Task.h
+++ b/src/wbase/Task.h
@@ -220,6 +220,7 @@ class Task : public util::CommandForThreadPool {
     int getJobId() const { return _jId; }
     int getAttemptCount() const { return _attemptCount; }
     bool getScanInteractive() { return _scanInteractive; }
+    int64_t getMaxTableSize() const { return _maxTableSize; }
     proto::ScanInfo& getScanInfo() { return _scanInfo; }
     void setOnInteractive(bool val) { _onInteractive = val; }
     bool getOnInteractive() { return _onInteractive; }
@@ -322,6 +323,7 @@ class Task : public util::CommandForThreadPool {
     bool _scanInteractive;  ///< True if the czar thinks this query should be interactive.
     bool _onInteractive{
             false};  ///< True if the scheduler put this task on the interactive (group) scheduler.
+    int64_t _maxTableSize = 0;
     std::atomic<memman::MemMan::Handle> _memHandle{memman::MemMan::HandleType::INVALID};
     memman::MemMan::Ptr _memMan;
 
diff --git a/src/wbase/TransmitData.cc b/src/wbase/TransmitData.cc
index 4cbe64f92..9ae3923f9 100644
--- a/src/wbase/TransmitData.cc
+++ b/src/wbase/TransmitData.cc
@@ -173,6 +173,7 @@ void TransmitData::_buildDataMsg(lock_guard<mutex> const& lock, Task const& task
         string msg = "Error(s) in result for chunk #" + to_string(task.getChunkId()) + ": " +
                      multiErr.toOneLineString();
         _result->set_errormsg(msg);
+        _result->set_errorcode(multiErr.firstErrorCode());
         LOGS(_log, LOG_LVL_ERROR, _idStr << "buildDataMsg adding " << msg);
     }
     _result->SerializeToString(&_dataMsg);