diff --git a/src/graphnet/data/dataconverter.py b/src/graphnet/data/dataconverter.py
index 69d13be50..57f6005f6 100644
--- a/src/graphnet/data/dataconverter.py
+++ b/src/graphnet/data/dataconverter.py
@@ -89,11 +89,14 @@ def __call__(self, input_dir: Union[str, List[str]]) -> None:
         # in the directory
         input_files = self._file_reader.find_files(path=input_dir)
         self._launch_jobs(input_files=input_files)
-        self._output_files = glob(
+        self._output_files = [
             os.path.join(
-                self._output_dir, f"*{self._save_method.file_extension}"
+                self._output_dir,
+                self._create_file_name(file)
+                + self._save_method.file_extension,
             )
-        )
+            for file in input_files
+        ]
 
     @final
     def _launch_jobs(
@@ -159,9 +162,10 @@ def _create_file_name(self, input_file_path: Union[str, I3FileSet]) -> str:
         if isinstance(input_file_path, I3FileSet):
             input_file_path = input_file_path.i3_file
         file_name = os.path.basename(input_file_path)
-        index_of_dot = file_name.index(".")
-        file_name_without_extension = file_name[:index_of_dot]
-        return file_name_without_extension
+        for ext in self._file_reader._accepted_file_extensions:
+            if file_name.endswith(ext):
+                file_name_without_extension = file_name.replace(ext, "")
+        return file_name_without_extension.replace(".i3", "")
 
     @final
     def _assign_event_no(
diff --git a/src/graphnet/data/extractors/icecube/i3genericextractor.py b/src/graphnet/data/extractors/icecube/i3genericextractor.py
index e907181d0..c79b7329b 100644
--- a/src/graphnet/data/extractors/icecube/i3genericextractor.py
+++ b/src/graphnet/data/extractors/icecube/i3genericextractor.py
@@ -45,6 +45,7 @@ def __init__(
         self,
         keys: Optional[Union[str, List[str]]] = None,
         exclude_keys: Optional[Union[str, List[str]]] = None,
+        extractor_name: str = GENERIC_EXTRACTOR_NAME,
     ):
         """Construct I3GenericExtractor.
 
@@ -72,7 +73,7 @@ def __init__(
         self._exclude_keys: Optional[List[str]] = exclude_keys
 
         # Base class constructor
-        super().__init__(GENERIC_EXTRACTOR_NAME)
+        super().__init__(extractor_name)
 
     def _get_keys(self, frame: "icetray.I3Frame") -> List[str]:
         """Get the list of keys to be queried from `frame`.
@@ -170,6 +171,12 @@ def __call__(self, frame: "icetray.I3Frame") -> Dict[str, Any]:
             # Flatten all other objects
             else:
                 results[key] = self._flatten_result(result)
+                if (
+                    isinstance(results[key], dict)
+                    and "value" in results[key]
+                    and len(results[key]) == 1
+                ):
+                    results[key] = results[key]["value"]
 
         # Serialise list of iterables to JSON
         results = {key: serialise(value) for key, value in results.items()}
diff --git a/src/graphnet/data/writers/sqlite_writer.py b/src/graphnet/data/writers/sqlite_writer.py
index d7cc48297..ab8d95051 100644
--- a/src/graphnet/data/writers/sqlite_writer.py
+++ b/src/graphnet/data/writers/sqlite_writer.py
@@ -181,6 +181,7 @@ def _merge_databases(
                     database_path=database_path,
                     index_column=primary_key,
                     integer_primary_key=integer_primary_key,
+                    default_type="FLOAT",
                 )
 
                 # Update row counts if needed