diff --git a/bigchaindb/backend/localmongodb/query.py b/bigchaindb/backend/localmongodb/query.py
index 557dfa1c..f99f3815 100644
--- a/bigchaindb/backend/localmongodb/query.py
+++ b/bigchaindb/backend/localmongodb/query.py
@@ -43,10 +43,10 @@ def store_metadata(conn, metadata):
 
 
 @register_query(LocalMongoDBConnection)
-def get_metadata(conn, txn_ids):
+def get_metadata(conn, transaction_ids):
     return conn.run(
         conn.collection('metadata')
-        .find({'id': {'$in': txn_ids}},
+        .find({'id': {'$in': transaction_ids}},
               projection={'_id': False}))
 
 
diff --git a/bigchaindb/backend/localmongodb/schema.py b/bigchaindb/backend/localmongodb/schema.py
index b42b1bb2..2d916856 100644
--- a/bigchaindb/backend/localmongodb/schema.py
+++ b/bigchaindb/backend/localmongodb/schema.py
@@ -94,7 +94,7 @@ def create_metadata_secondary_index(conn, dbname):
 
     # the id is the txid of the transaction where metadata was defined
     conn.conn[dbname]['metadata'].create_index('id',
-                                               name='txn_id',
+                                               name='transaction_id',
                                                unique=True)
 
     # full text search index
diff --git a/bigchaindb/backend/query.py b/bigchaindb/backend/query.py
index f8ea879f..766d6668 100644
--- a/bigchaindb/backend/query.py
+++ b/bigchaindb/backend/query.py
@@ -35,10 +35,10 @@ def store_asset(connection, asset):
 
 @singledispatch
 def store_metadata(connection, metadata):
-    """Write an asset to the asset table.
+    """Write metadata to the metadata table.
 
     Args:
-        asset (dict): the asset.
+        metadata (dict): transaction metadata.
 
     Returns:
         The result of the operation.
@@ -345,11 +345,11 @@ def get_assets(connection, asset_ids):
 
 
 @singledispatch
-def get_metadata(connection, txn_ids):
+def get_metadata(connection, transaction_ids):
     """Get a list of metadata from the metadata table.
 
     Args:
-        txn_ids (list): a list of ids for the metadata to be retrieved from
+        transaction_ids (list): a list of ids for the metadata to be retrieved from
         the database.
 
     Returns:
diff --git a/bigchaindb/tendermint/lib.py b/bigchaindb/tendermint/lib.py
index 6247f96e..37fb9d6e 100644
--- a/bigchaindb/tendermint/lib.py
+++ b/bigchaindb/tendermint/lib.py
@@ -52,10 +52,10 @@ class BigchainDB(Bigchain):
                 backend.query.store_asset(self.connection, asset)
 
         metadata = transaction.pop('metadata')
-        txn_metadata = {'id': transaction['id'],
-                        'metadata': metadata}
+        transaction_metadata = {'id': transaction['id'],
+                                'metadata': metadata}
 
-        backend.query.store_metadata(self.connection, [txn_metadata])
+        backend.query.store_metadata(self.connection, [transaction_metadata])
 
         return backend.query.store_transaction(self.connection, transaction)