Remove promoted notes temporary index

changelogs/unreleased/issue_205690.yml

+---
+title: Remove promoted notes temporary index
+merge_request: 26896
+author:
+type: other

db/post_migrate/20200310135818_remove_temporary_promoted_notes_index.rb

+# frozen_string_literal: true
+
+# Removes temporary index to fix orphan promoted issues.
+# For more information check: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23916
+class RemoveTemporaryPromotedNotesIndex < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    remove_concurrent_index_by_name :notes, 'tmp_idx_on_promoted_notes'
+  end
+
+  def down
+    add_concurrent_index :notes,
+      :note,
+      where: "noteable_type = 'Issue' AND system IS TRUE AND note LIKE 'promoted to epic%'",
+      name: 'tmp_idx_on_promoted_notes'
+  end
+end

db/schema.rb

@@ -2844,7 +2844,6 @@ ActiveRecord::Schema.define(version: 2020_03_11_165635) do
     t.index ["id", "noteable_type"], name: "note_mentions_temp_index", where: "(note ~~ '%@%'::text)"
     t.index ["line_code"], name: "index_notes_on_line_code"
     t.index ["note"], name: "index_notes_on_note_trigram", opclass: :gin_trgm_ops, using: :gin
-    t.index ["note"], name: "tmp_idx_on_promoted_notes", where: "(((noteable_type)::text = 'Issue'::text) AND (system IS TRUE) AND (note ~~ 'promoted to epic%'::text))"
     t.index ["noteable_id", "noteable_type"], name: "index_notes_on_noteable_id_and_noteable_type"
     t.index ["project_id", "id"], name: "index_notes_on_project_id_and_id_and_system_false", where: "(NOT system)"
     t.index ["project_id", "noteable_type"], name: "index_notes_on_project_id_and_noteable_type"