perf: Improve performance of record message serialization

singer_sdk/_singerlib/messages.py

@@ -79,6 +79,26 @@ class RecordMessage(Message):
     time_extracted: datetime | None = None
     """The time the record was extracted."""
 
+    def to_dict(self) -> dict[str, t.Any]:
+        """Return a dictionary representation of the message.
+
+        This overrides the default conversion logic, since it uses unnecessary
+        deep copying and is very slow.
+
+        Returns:
+            A dictionary with the defined message fields.
+        """
+        result: dict[str, t.Any] = {
+            "type": "RECORD",
+            "stream": self.stream,
+            "record": self.record,
+        }
+        if self.version is not None:
+            result["version"] = self.version
+        if self.time_extracted is not None:
+            result["time_extracted"] = self.time_extracted
+        return result
+
     def __post_init__(self) -> None:
         """Post-init processing.