Add ancillary indexes to improve deletion. (#4508)

Provider deletion, or entity deletion in general, runs into
performance problems without this indexes as two triggers for
constraint were executing full table scans on pretty crowded tables.

These two indexes solve that problem.

database/migrations/000106_ancillary_evaluation_indexes.down.sql

@@ -0,0 +1,22 @@
+-- Copyright 2024 Stacklok, Inc
+--
+-- 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.
+
+BEGIN;
+
+-- The following two indexes on alert_events and remediation_events
+-- are necessary to optimize deletions.
+DROP INDEX alert_events_evaluation_id_fk_idx;
+DROP INDEX remediation_events_evaluation_id_fk_idx;
+
+COMMIT;

database/migrations/000106_ancillary_evaluation_indexes.up.sql

@@ -0,0 +1,22 @@
+-- Copyright 2024 Stacklok, Inc
+--
+-- 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.
+
+BEGIN;
+
+-- The following two indexes on alert_events and remediation_events
+-- are necessary to optimize deletions.
+CREATE INDEX alert_events_evaluation_id_fk_idx ON alert_events (evaluation_id);
+CREATE INDEX remediation_events_evaluation_id_fk_idx ON remediation_events (evaluation_id);
+
+COMMIT;