Adding note about unique .db file

docs/articles/data_storage.rst

@@ -138,6 +138,10 @@ Once the storage location is known, the first step to migrate the project or fol
 of its contents using the
 `index_files_for_migration <synapseutils.html#synapseutils.migrate_functions.index_files_for_migration>`__ function, e.g.
 
+When specifying the `.db` file for the migratable indexes you need to specify a `.db` file that does not already exist 
+for another synapse project or folder on disk. It is the best practice to specify a unique name for the file by including
+the synapse id in the name of the file, or other unique identifier.
+
   .. code-block::
 
     import synapseutils
@@ -149,7 +153,7 @@ of its contents using the
     # nothing needs to exist at this path, but it must be a valid path on a volume with sufficient
     # disk space to store a meta data listing of all the contents in the indexed entity.
     # a rough rule of thumb is 100kB per 1000 entities indexed.
-    db_path = '/tmp/foo/bar.db'
+    db_path = '/tmp/foo/syn123_bar.db'
 
     result = synapseutils.index_files_for_migration(
         syn,
@@ -207,7 +211,7 @@ Putting all the migration pieces together
     # # nothing needs to exist at this path, but it must be a valid path on a volume with sufficient
     # # disk space to store a meta data listing of all the contents in the indexed entity.
     # # a rough rule of thumb is 100kB per 1000 entities indexed.
-    db_path = os.path.expanduser("~/synapseMigration/my.db")
+    db_path = os.path.expanduser(f"~/synapseMigration/{my_synapse_project_or_folder_to_migrate}_my.db")
 
     syn = synapseclient.Synapse()
 
@@ -253,7 +257,7 @@ Putting all the migration pieces together
 The result of running this should look like
   .. code-block::
 
-    Indexing: syn123 for migration to storage_id: 11111 at: /home/user/synapseMigration/my.db
+    Indexing: syn123 for migration to storage_id: 11111 at: /home/user/synapseMigration/syn123_my.db
     Indexing result: {'INDEXED': 100, 'MIGRATED': 0, 'ALREADY_MIGRATED': 0, 'ERRORED': 0}
     Migrating files...
     Migration result: {'INDEXED': 0, 'MIGRATED': 100, 'ALREADY_MIGRATED': 0, 'ERRORED': 0}