Remove unused index for confidence level migrations

We used these indexes due to size of the data
we wanted to change. This is a follow up
mr to remove those unused indexes

db/post_migrate/20200527094322_drop_vulnerability_confidence_index.rb

+# frozen_string_literal: true
+
+class DropVulnerabilityConfidenceIndex < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  DOWNTIME = false
+  INDEX_NAME = 'index_vulnerability_on_id_and_confidence_eq_zero'
+
+  def up
+    Gitlab::BackgroundMigration.steal('RemoveUndefinedVulnerabilityConfidenceLevel')
+
+    remove_concurrent_index_by_name :vulnerabilities, INDEX_NAME
+  end
+
+  def down
+    add_concurrent_index(:vulnerabilities, :id, where: 'confidence = 0', name: INDEX_NAME)
+  end
+end

db/post_migrate/20200527095401_drop_vulnerability_occurrence_confidence_index.rb

+# frozen_string_literal: true
+
+class DropVulnerabilityOccurrenceConfidenceIndex < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  DOWNTIME = false
+  INDEX_NAME = 'index_vulnerability_occurrences_on_id_and_confidence_eq_zero'
+
+  def up
+    Gitlab::BackgroundMigration.steal('RemoveUndefinedOccurrenceConfidenceLevel')
+
+    remove_concurrent_index_by_name :vulnerability_occurrences, INDEX_NAME
+  end
+
+  def down
+    add_concurrent_index(:vulnerability_occurrences, :id, where: 'confidence = 0', name: INDEX_NAME)
+  end
+end

db/structure.sql

@@ -10942,8 +10942,6 @@ CREATE UNIQUE INDEX index_vulnerability_occurrence_identifiers_on_unique_keys ON
 
 CREATE INDEX index_vulnerability_occurrence_pipelines_on_pipeline_id ON public.vulnerability_occurrence_pipelines USING btree (pipeline_id);
 
-CREATE INDEX index_vulnerability_occurrences_on_id_and_confidence_eq_zero ON public.vulnerability_occurrences USING btree (id) WHERE (confidence = 0);
-
 CREATE INDEX index_vulnerability_occurrences_on_primary_identifier_id ON public.vulnerability_occurrences USING btree (primary_identifier_id);
 
 CREATE INDEX index_vulnerability_occurrences_on_scanner_id ON public.vulnerability_occurrences USING btree (scanner_id);
@@ -10954,8 +10952,6 @@ CREATE UNIQUE INDEX index_vulnerability_occurrences_on_uuid ON public.vulnerabil
 
 CREATE INDEX index_vulnerability_occurrences_on_vulnerability_id ON public.vulnerability_occurrences USING btree (vulnerability_id);
 
-CREATE INDEX index_vulnerability_on_id_and_confidence_eq_zero ON public.vulnerabilities USING btree (id) WHERE (confidence = 0);
-
 CREATE UNIQUE INDEX index_vulnerability_scanners_on_project_id_and_external_id ON public.vulnerability_scanners USING btree (project_id, external_id);
 
 CREATE UNIQUE INDEX index_vulnerability_user_mentions_on_note_id ON public.vulnerability_user_mentions USING btree (note_id) WHERE (note_id IS NOT NULL);
@@ -13966,5 +13962,7 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200526120714
 20200526164946
 20200526164947
+20200527094322
+20200527095401
 \.
 

ee/changelogs/unreleased/drop-unused-confidence-index.yml

+---
+title: Remove unused index for vulnerabiliy confidence levels
+merge_request: 33149
+author:
+type: other