Query plan gate

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "molodetz"
-version = "1.0.2"
+version = "1.0.3"
 description = "Molodetz, a calm community blog roll."
 readme = "README.md"
 requires-python = ">=3.12"

tests/unit/test_query_plans.py

@@ -0,0 +1,27 @@
+# retoor <retoor@molodetz.nl>
+import sqlite3
+
+import pytest
+
+from tests.conftest import TEST_DATA_DIR
+
+QUERIES = [
+    ("idx_posts_published", "SELECT * FROM posts WHERE topic = 'rol' AND status = 'published' AND deleted_at IS NULL ORDER BY published_at DESC LIMIT 25"),
+    ("idx_posts_slug", "SELECT * FROM posts WHERE slug = 'x'"),
+    ("idx_sessions_token", "SELECT * FROM sessions WHERE token = 'x'"),
+    ("idx_users_api_key", "SELECT * FROM users WHERE api_key = 'x'"),
+    ("idx_media_items_kind", "SELECT * FROM media_items WHERE kind = 'flyer' AND deleted_at IS NULL ORDER BY position, id"),
+    ("idx_notifications_user", "SELECT * FROM notifications WHERE user_uid = 'x' ORDER BY created_at DESC LIMIT 50"),
+    ("idx_audit_log_created", "SELECT uid FROM audit_log WHERE created_at < '2020-01-01'"),
+]
+
+
+@pytest.mark.parametrize("index,sql", QUERIES, ids=[item[0] for item in QUERIES])
+def test_index_is_used_without_temp_btree(app_server, index, sql):
+    connection = sqlite3.connect(TEST_DATA_DIR / "molodetz.db")
+    try:
+        plan = " | ".join(row[-1] for row in connection.execute(f"EXPLAIN QUERY PLAN {sql}"))
+    finally:
+        connection.close()
+    assert f"USING INDEX {index}" in plan or f"USING COVERING INDEX {index}" in plan, plan
+    assert "TEMP B-TREE" not in plan, plan