Remove unused index for broken location fingerprints

changelogs/unreleased/remove-tmp-index.yml

+---
+title: Remove temporary index for fixing broken CS fingerprints
+merge_request: 43126
+author:
+type: other

db/migrate/20200923130057_remove_tmp_container_scanning_index.rb

+# frozen_string_literal: true
+
+class RemoveTmpContainerScanningIndex < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'tmp_index_for_fixing_inconsistent_vulnerability_occurrences'
+  disable_ddl_transaction!
+
+  def up
+    remove_concurrent_index_by_name(:vulnerability_occurrences, INDEX_NAME)
+  end
+
+  def down
+    # report_type: 2 container scanning
+    add_concurrent_index(:vulnerability_occurrences, :id,
+      where: "LENGTH(location_fingerprint) = 40 AND report_type = 2",
+      name: INDEX_NAME)
+  end
+end

db/schema_migrations/20200923130057

+84b272d61f6ab6e9f9f8eb059ba139a3fa0d2f1bbeb337f2e4e7cd4034822b44
\ No newline at end of file

db/structure.sql

@@ -21576,8 +21576,6 @@ CREATE INDEX tmp_build_stage_position_index ON ci_builds USING btree (stage_id,
 
 CREATE INDEX tmp_index_for_email_unconfirmation_migration ON emails USING btree (id) WHERE (confirmed_at IS NOT NULL);
 
-CREATE INDEX tmp_index_for_fixing_inconsistent_vulnerability_occurrences ON vulnerability_occurrences USING btree (id) WHERE ((length(location_fingerprint) = 40) AND (report_type = 2));
-
 CREATE UNIQUE INDEX unique_merge_request_metrics_by_merge_request_id ON merge_request_metrics USING btree (merge_request_id);
 
 CREATE UNIQUE INDEX users_security_dashboard_projects_unique_index ON users_security_dashboard_projects USING btree (project_id, user_id);