Add temporary index to `vulnerabilities` table

db/migrate/20201102231721_add_temporary_index_to_vulnerabilities_table.rb

+# frozen_string_literal: true
+
+class AddTemporaryIndexToVulnerabilitiesTable < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'temporary_index_vulnerabilities_on_id'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :vulnerabilities, :id, where: "state = 2 AND (dismissed_at IS NULL OR dismissed_by_id IS NULL)", name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name :vulnerabilities, INDEX_NAME
+  end
+end

db/schema_migrations/20201102231721

+2aa43de4e88dae59b117d6479f6c5d113bda1e0bce4290bf6103f1b9f7694917
\ No newline at end of file

db/structure.sql

@@ -22200,6 +22200,8 @@ CREATE UNIQUE INDEX snippet_user_mentions_on_snippet_id_index ON snippet_user_me
 
 CREATE UNIQUE INDEX taggings_idx ON taggings USING btree (tag_id, taggable_id, taggable_type, context, tagger_id, tagger_type);
 
+CREATE INDEX temporary_index_vulnerabilities_on_id ON vulnerabilities USING btree (id) WHERE ((state = 2) AND ((dismissed_at IS NULL) OR (dismissed_by_id IS NULL)));
+
 CREATE UNIQUE INDEX term_agreements_unique_index ON term_agreements USING btree (user_id, term_id);
 
 CREATE INDEX terraform_state_versions_verification_checksum_partial ON terraform_state_versions USING btree (verification_checksum) WHERE (verification_checksum IS NOT NULL);