diff --git a/bigchaindb/backend/query.py b/bigchaindb/backend/query.py
index 88f215c4..930fb3e1 100644
--- a/bigchaindb/backend/query.py
+++ b/bigchaindb/backend/query.py
@@ -318,3 +318,18 @@ def get_unvoted_blocks(connection, node_pubkey):
     """
 
     raise NotImplementedError
+
+
+@singledispatch
+def get_old_transactions(connection, node_pubkey):
+    """Return all the transactions from the backlog that have not been
+       processed by the specified node.
+
+    Args:
+        node_pubkey (str): base58 encoded public key
+
+    Returns:
+        :obj:`list` of :obj:`dict`: a list of unprocessed transactions
+    """
+
+    raise NotImplementedError
diff --git a/bigchaindb/backend/rethinkdb/query.py b/bigchaindb/backend/rethinkdb/query.py
index 8fa6a512..57563ad3 100644
--- a/bigchaindb/backend/rethinkdb/query.py
+++ b/bigchaindb/backend/rethinkdb/query.py
@@ -244,3 +244,14 @@ def get_unvoted_blocks(connection, node_pubkey):
     #        database level. Solving issue #444 can help untangling the situation
     unvoted_blocks = filter(lambda block: not util.is_genesis_block(block), unvoted)
     return unvoted_blocks
+
+
+@register_query(RethinkDBConnection)
+def get_old_transactions(connection, node_pubkey):
+    return connection.run(
+        r.table('backlog')
+         .between([node_pubkey, r.minval],
+                  [node_pubkey, r.maxval],
+                  index='assignee__transaction_timestamp')
+         .order_by(index=r.asc('assignee_transaction_timestamp'))
+    )
diff --git a/bigchaindb/core.py b/bigchaindb/core.py
index f0e1b89c..5a61f117 100644
--- a/bigchaindb/core.py
+++ b/bigchaindb/core.py
@@ -676,3 +676,15 @@ class Bigchain(object):
                 return Bigchain.BLOCK_INVALID
         else:
             return Bigchain.BLOCK_UNDECIDED
+
+    def get_old_transactions(self):
+        """Return all the transactions from the backlog that have not been
+           processed by the specified node.
+
+        Args:
+            node_pubkey (str): base58 encoded public key
+
+        Returns:
+            :obj:`list` of :obj:`dict`: a list of unprocessed transactions
+        """
+        return backend.query.get_old_transactions(self.connection, self.me)
diff --git a/bigchaindb/pipelines/block.py b/bigchaindb/pipelines/block.py
index dc0e1163..d7cc2735 100644
--- a/bigchaindb/pipelines/block.py
+++ b/bigchaindb/pipelines/block.py
@@ -6,9 +6,7 @@ function.
 """
 
 import logging
-
-import rethinkdb as r
-from multipipes import Pipeline, Node, Pipe
+from multipipes import Pipeline, Node
 
 import bigchaindb
 from bigchaindb.backend import connect
@@ -119,7 +117,8 @@ class BlockPipeline:
         Returns:
             :class:`~bigchaindb.models.Block`: The Block.
         """
-        logger.info('Write new block %s with %s transactions', block.id, len(block.transactions))
+        logger.info('Write new block %s with %s transactions',
+                    block.id, len(block.transactions))
         self.bigchain.write_block(block)
         return block
 
@@ -142,12 +141,7 @@ def initial():
 
     bigchain = Bigchain()
 
-    return bigchain.connection.run(
-        r.table('backlog')
-        .between([bigchain.me, r.minval],
-                 [bigchain.me, r.maxval],
-                 index='assignee__transaction_timestamp')
-        .order_by(index=r.asc('assignee__transaction_timestamp')))
+    return bigchain.get_old_transactions()
 
 
 def create_pipeline():