diff --git a/inbox/api/filtering.py b/inbox/api/filtering.py
index fd81f83d5..a82cbf471 100644
--- a/inbox/api/filtering.py
+++ b/inbox/api/filtering.py
@@ -22,7 +22,7 @@
 from inbox.models.session import session_scope_by_shard_id
 
 
-def contact_subquery(db_session, namespace_id, email_address, field):
+def contact_query(db_session, namespace_id, email_address, field):
     return (
         db_session.query(Message.thread_id)
         .join(MessageContactAssociation)
@@ -32,7 +32,6 @@ def contact_subquery(db_session, namespace_id, email_address, field):
             Contact.namespace_id == namespace_id,
             MessageContactAssociation.field == field,
         )
-        .subquery()
     )
 
 
@@ -89,19 +88,19 @@ def threads(
     query = query.filter(*filters)
 
     if from_addr is not None:
-        from_query = contact_subquery(db_session, namespace_id, from_addr, "from_addr")
+        from_query = contact_query(db_session, namespace_id, from_addr, "from_addr")
         query = query.filter(Thread.id.in_(from_query))
 
     if to_addr is not None:
-        to_query = contact_subquery(db_session, namespace_id, to_addr, "to_addr")
+        to_query = contact_query(db_session, namespace_id, to_addr, "to_addr")
         query = query.filter(Thread.id.in_(to_query))
 
     if cc_addr is not None:
-        cc_query = contact_subquery(db_session, namespace_id, cc_addr, "cc_addr")
+        cc_query = contact_query(db_session, namespace_id, cc_addr, "cc_addr")
         query = query.filter(Thread.id.in_(cc_query))
 
     if bcc_addr is not None:
-        bcc_query = contact_subquery(db_session, namespace_id, bcc_addr, "bcc_addr")
+        bcc_query = contact_query(db_session, namespace_id, bcc_addr, "bcc_addr")
         query = query.filter(Thread.id.in_(bcc_query))
 
     if any_email is not None:
@@ -113,7 +112,6 @@ def threads(
                 Contact.email_address.in_(any_email),
                 Contact.namespace_id == namespace_id,
             )
-            .subquery()
         )
         query = query.filter(Thread.id.in_(any_contact_query))
 
@@ -129,7 +127,6 @@ def threads(
             .join(Part)
             .join(Block)
             .filter(Block.filename == filename, Block.namespace_id == namespace_id)
-            .subquery()
         )
         query = query.filter(Thread.id.in_(files_query))
 
@@ -146,24 +143,19 @@ def threads(
             .join(Message.messagecategories)
             .join(MessageCategory.category)
             .filter(Category.namespace_id == namespace_id, or_(*category_filters))
-            .subquery()
         )
         query = query.filter(Thread.id.in_(category_query))
 
     if unread is not None:
         read = not unread
-        unread_query = (
-            db_session.query(Message.thread_id)
-            .filter(Message.namespace_id == namespace_id, Message.is_read == read)
-            .subquery()
+        unread_query = db_session.query(Message.thread_id).filter(
+            Message.namespace_id == namespace_id, Message.is_read == read
         )
         query = query.filter(Thread.id.in_(unread_query))
 
     if starred is not None:
-        starred_query = (
-            db_session.query(Message.thread_id)
-            .filter(Message.namespace_id == namespace_id, Message.is_starred == starred)
-            .subquery()
+        starred_query = db_session.query(Message.thread_id).filter(
+            Message.namespace_id == namespace_id, Message.is_starred == starred
         )
         query = query.filter(Thread.id.in_(starred_query))
 
@@ -344,7 +336,6 @@ def messages_or_drafts(
                 Contact.email_address == to_addr,
                 Contact.namespace_id == bindparam("namespace_id"),
             )
-            .subquery()
         )
         query = query.filter(Message.id.in_(to_query))
 
@@ -357,7 +348,6 @@ def messages_or_drafts(
                 Contact.email_address == from_addr,
                 Contact.namespace_id == bindparam("namespace_id"),
             )
-            .subquery()
         )
         query = query.filter(Message.id.in_(from_query))
 
@@ -370,7 +360,6 @@ def messages_or_drafts(
                 Contact.email_address == cc_addr,
                 Contact.namespace_id == bindparam("namespace_id"),
             )
-            .subquery()
         )
         query = query.filter(Message.id.in_(cc_query))
 
@@ -383,7 +372,6 @@ def messages_or_drafts(
                 Contact.email_address == bcc_addr,
                 Contact.namespace_id == bindparam("namespace_id"),
             )
-            .subquery()
         )
         query = query.filter(Message.id.in_(bcc_query))
 
@@ -395,7 +383,6 @@ def messages_or_drafts(
                 Contact.email_address.in_(any_email),
                 Contact.namespace_id == bindparam("namespace_id"),
             )
-            .subquery()
         )
         query = query.filter(Message.id.in_(any_email_query))
 
@@ -583,7 +570,7 @@ def recurring_events(
     if ends_before:
         # start < end, so event start < ends_before
         before_criteria.append(RecurringEvent.start < ends_before)
-    recur_query = recur_query.filter(and_(*before_criteria))
+    recur_query = recur_query.filter(*before_criteria)
     after_criteria = []
     if starts_after:
         after_criteria.append(
@@ -594,7 +581,7 @@ def recurring_events(
             or_(RecurringEvent.until > ends_after, RecurringEvent.until.is_(None))
         )
 
-    recur_query = recur_query.filter(and_(*after_criteria))
+    recur_query = recur_query.filter(*after_criteria)
 
     recur_instances = []
 
@@ -694,7 +681,6 @@ def events(
                 Contact.namespace_id == namespace_id,
                 EventContactAssociation.field == "title",
             )
-            .subquery()
         )
         event_criteria.append(Event.id.in_(title_email_query))
 
@@ -707,7 +693,6 @@ def events(
                 Contact.namespace_id == namespace_id,
                 EventContactAssociation.field == "description",
             )
-            .subquery()
         )
         event_criteria.append(Event.id.in_(description_email_query))
 
@@ -720,7 +705,6 @@ def events(
                 Contact.namespace_id == namespace_id,
                 EventContactAssociation.field == "owner",
             )
-            .subquery()
         )
         event_criteria.append(Event.id.in_(owner_email_query))
 
@@ -733,7 +717,6 @@ def events(
                 Contact.namespace_id == namespace_id,
                 EventContactAssociation.field == "participant",
             )
-            .subquery()
         )
         event_criteria.append(Event.id.in_(participant_email_query))
 
@@ -744,7 +727,6 @@ def events(
             .filter(
                 Contact.email_address == any_email, Contact.namespace_id == namespace_id
             )
-            .subquery()
         )
         event_criteria.append(Event.id.in_(any_email_query))
 
diff --git a/inbox/models/session.py b/inbox/models/session.py
index 22fd644a2..feda46894 100644
--- a/inbox/models/session.py
+++ b/inbox/models/session.py
@@ -211,7 +211,7 @@ def id_chooser(query, ident):
     return [str(engine_manager.shard_key_for_id(ident))]
 
 
-def query_chooser(query):
+def execute_chooser(query):
     return [str(k) for k in engine_manager.engines]
 
 
@@ -221,7 +221,7 @@ def global_session_scope():
     session = ShardedSession(
         shard_chooser=shard_chooser,
         id_chooser=id_chooser,
-        query_chooser=query_chooser,
+        execute_chooser=execute_chooser,
         shards=shards,
     )
     # STOPSHIP(emfree): need instrumentation and proper exception handling
diff --git a/inbox/transactions/delta_sync.py b/inbox/transactions/delta_sync.py
index 7e944ac6e..edc7e5cb6 100644
--- a/inbox/transactions/delta_sync.py
+++ b/inbox/transactions/delta_sync.py
@@ -57,7 +57,7 @@ def get_transaction_cursor_near_timestamp(namespace_id, timestamp, db_session):
         .order_by(desc(Transaction.created_at))
         .filter(Transaction.created_at < dt, Transaction.namespace_id == namespace_id)
         .limit(1)
-        .subquery()
+        .scalar_subquery()
     )
     latest_transaction = (
         db_session.query(Transaction)