Improve the performance of get_view_names in SQLAlchemy

Author: john-bodley

tests/integration/test_sqlalchemy_integration.py

@@ -409,3 +409,43 @@ def test_get_table_names_raises(trino_connection):
 
     with pytest.raises(sqla.exc.NoSuchTableError):
         sqla.inspect(engine).get_table_names(None)
+
+
+@pytest.mark.parametrize('trino_connection', ['memory/test'], indirect=True)
+@pytest.mark.parametrize('schema', [None, 'test'])
+def test_get_view_names(trino_connection, schema):
+    engine, conn = trino_connection
+    name = schema or engine.dialect._get_default_schema_name(conn)
+    metadata = sqla.MetaData(schema=name)
+
+    if not engine.dialect.has_schema(conn, name):
+        engine.execute(sqla.schema.CreateSchema(name))
+
+    try:
+        create_view(
+            'test_get_view_names',
+            sqla.select(
+                [
+                    sqla.Table(
+                        'my_table',
+                        metadata,
+                        sqla.Column('id', sqla.Integer),
+                    ),
+                ],
+            ),
+            metadata,
+            cascade_on_drop=False,
+        )
+
+        metadata.create_all(engine)
+        assert sqla.inspect(engine).get_view_names(schema) == ['test_get_view_names']
+    finally:
+        metadata.drop_all(engine)
+
+
+@pytest.mark.parametrize('trino_connection', ['memory'], indirect=True)
+def test_get_view_names_raises(trino_connection):
+    engine, _ = trino_connection
+
+    with pytest.raises(sqla.exc.NoSuchTableError):
+        sqla.inspect(engine).get_view_names(None)

trino/sqlalchemy/dialect.py

@@ -215,11 +215,14 @@ def get_view_names(self, connection: Connection, schema: str = None, **kw) -> Li
         schema = schema or self._get_default_schema_name(connection)
         if schema is None:
             raise exc.NoSuchTableError("schema is required")
+
+        # Querying the information_schema.views table is subpar as it compiles the view definitions.
         query = dedent(
             """
             SELECT "table_name"
-            FROM "information_schema"."views"
+            FROM "information_schema"."tables"
             WHERE "table_schema" = :schema
+              AND "table_type" = 'VIEW'
         """
         ).strip()
         res = connection.execute(sql.text(query), schema=schema)