change save new gconstruct config behavior

docs/source/configuration/configuration-gconstruction.rst

@@ -19,6 +19,7 @@ Graph Construction
 * **-\-skip-nonexist-edges**: boolean value to decide whether skip edges whose endpoint nodes don't exist. Default is true.
 * **-\-ext-mem-workspace**: the directory where the tool can store data during graph construction. Suggest to use high-speed SSD as the external memory workspace.
 * **-\-ext-mem-feat-size**: the minimal number of feature dimensions that features can be stored in external memory. Default is 64.
+* **-\-output-conf-file**: The output file with the updated configurations that records the details of data transformation, e.g., one-hot encoding maps, max-min normalization ranges. If not specified, will save the updated configuration file in the **-\-output-dir** with name `data_transform_new.json`.
 
 .. _gconstruction-json:
 

python/graphstorm/gconstruct/construct_graph.py

@@ -771,9 +771,13 @@ def process_graph(args):
     sys_tracker.check('Process the edge data')
     num_nodes = {ntype: len(raw_node_id_maps[ntype]) for ntype in raw_node_id_maps}
     if args.output_conf_file is not None:
-        # Save the new config file.
-        with open(args.output_conf_file, "w", encoding="utf8") as outfile:
-            json.dump(process_confs, outfile, indent=4)
+        outfile_path = args.output_conf_file
+    else:
+        outfile_path = os.path.join(args.output_dir, 'data_transform_new.json')
+
+    # Save the new config file.
+    with open(outfile_path, "w", encoding="utf8") as outfile:
+        json.dump(process_confs, outfile, indent=4)
 
     if args.add_reverse_edges:
         edges1 = {}