From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 1 Jun 2020 20:26:41 +0000 (-0400)
Subject: Add a test / comment about test_orm_query
X-Git-Tag: rel_1_4_0b1~286
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b05c8a0ef8b6e7bfd169a21e7c1f834fdb00da19;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

Add a test / comment about test_orm_query

Change-Id: I8d78b3e75127141da177f711fd91216391a3c859
---

diff --git a/examples/performance/short_selects.py b/examples/performance/short_selects.py
index 2f2b19c17d..64d9b05516 100644
--- a/examples/performance/short_selects.py
+++ b/examples/performance/short_selects.py
@@ -75,6 +75,25 @@ def test_orm_query(n):
         session.query(Customer).filter(Customer.id == id_).one()
 
 
+@Profiler.profile
+def test_orm_query_newstyle(n):
+    """test a straight ORM query of the full entity."""
+
+    # the newstyle query is faster for the following reasons:
+    # 1. it uses LABEL_STYLE_DISAMBIGUATE_ONLY, which saves on a huge amount
+    # of label generation and compilation calls
+    # 2. it does not use the Query @_assertions decorators.
+
+    # however, both test_orm_query and test_orm_query_newstyle are still
+    # 25-30% slower than the full blown Query version in 1.3.x and this
+    # continues to be concerning.
+
+    session = Session(bind=engine)
+    for id_ in random.sample(ids, n):
+        stmt = future_select(Customer).where(Customer.id == id_)
+        session.execute(stmt).scalars().unique().one()
+
+
 @Profiler.profile
 def test_orm_query_cols_only(n):
     """test an ORM query of only the entity columns."""