Deannotate ORM columns in ColumnEntity

Fixed a minor performance issue which could in some cases add unnecessary
overhead to result fetching, involving the use of ORM columns and entities
that include those same columns at the same time within a query.  The issue
has to do with hash / eq overhead when referring to the column in different
ways.

Fixes: #4347
Change-Id: I191d4d1b1623898060a9accdfd186de16f89a6b7

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index bfddb5cfe..cace2e54a 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -4243,6 +4243,11 @@ class _ColumnEntity(_QueryEntity):
         else:
             column = query._adapt_clause(self.column, False, True)
 
+        if column._annotations:
+            # annotated columns perform more slowly in compiler and
+            # result due to the __eq__() method, so use deannotated
+            column = column._deannotate()
+
         if context.adapter:
             column = context.adapter.columns[column]
 
@@ -4251,6 +4256,12 @@ class _ColumnEntity(_QueryEntity):
 
     def setup_context(self, query, context):
         column = query._adapt_clause(self.column, False, True)
+
+        if column._annotations:
+            # annotated columns perform more slowly in compiler and
+            # result due to the __eq__() method, so use deannotated
+            column = column._deannotate()
+
         context.froms += tuple(self.froms)
         context.primary_columns.append(column)