Add migration to cleanup and add additional indexes

This commit adds a migration which adds an additional composite index
on id, test_id in the tests table. This is needed to help with the
performance of queries that are being generated by the openstack-health
dashboard's rest api. As part of this migration though some additional
cruft in the test_run indexes is cleaned up. We accidently were ending
up with duplicate indexes on the id columns in the test_runs table.
This removes the duplicate and fixes the check to ensure new DBs
don't end up with duplicate indexes.

Change-Id: I9d4d42aaa6232db0b2ddfaf8d1a5f079cbeb6b31

subunit2sql/migrations/versions/b96122f780_cleanup_and_improve_indexes.py

@@ -0,0 +1,50 @@
+# Copyright 2015 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""Cleanup and Improve Indexes
+
+Revision ID: b96122f780
+Revises: 2fb76f1a1393
+Create Date: 2015-10-14 12:03:26.965724
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'b96122f780'
+down_revision = '2fb76f1a1393'
+
+from alembic import context
+from alembic import op
+from sqlalchemy.engine import reflection
+
+
+def upgrade():
+    migration_context = context.get_context()
+    insp = reflection.Inspector(migration_context.bind)
+    test_run_indx = insp.get_indexes('test_runs')
+    test_run_indx_names = [x['name'] for x in test_run_indx]
+    # Cleanup any duplicate indexes on test_runs
+    if 'ix_test_runs_test_id' in test_run_indx_names:
+        if 'ix_test_run_test_id' in test_run_indx_names:
+            op.drop_index('ix_test_run_test_id', 'test_runs')
+    if 'ix_test_runs_run_id' in test_run_indx_names:
+        if 'ix_test_run_run_id' in test_run_indx_names:
+            op.drop_index('ix_test_run_run_id', 'test_runs')
+
+    # Add an index for test, test_id
+    op.create_index('ix_test_ids', 'tests', ['id', 'test_id'], mysql_length=30)
+
+
+def downgrade():
+    pass

subunit2sql/tests/migrations/test_migrations.py

@@ -22,6 +22,7 @@ import os
 from alembic import config
 from alembic import script
 import sqlalchemy
+from sqlalchemy.engine import reflection
 
 from subunit2sql import exceptions as exc
 from subunit2sql.tests import base
@@ -381,3 +382,19 @@ class TestWalkMigrations(base.TestCase):
         res = list(test_metadata.select().execute())[0]
         self.assertEqual(res.id, data['id'])
         self.assertEqual(res.test_id, data['test_run_id'])
+
+    def _pre_upgrade_b96122f780(self, engine):
+        # NOTE(mtreinish) Return fake data to ensure we run check, this
+        # is needed because the framework normall assumes you're preseeded
+        # data is in the correct state post migration. But this time all we
+        # want to do is ensure a single index exists so that isn't needed
+        return 'data'
+
+    def _check_b96122f780(self, engine, data):
+        insp = reflection.Inspector(engine)
+        indxs = insp.get_indexes('test_runs')
+        # Check that we don't duplicate indexes anymore
+        tests = [indx for indx in indxs if ['test_id'] == indx['column_names']]
+        runs = [indx for indx in indxs if indx['column_names'] == ['run_id']]
+        self.assertEqual(1, len(tests))
+        self.assertEqual(1, len(runs))