From 13837fb8df5a7fb7788487d471fb289618b23138 Mon Sep 17 00:00:00 2001
From: Andreas Brandl <abrandl@gitlab.com>
Date: Tue, 10 Sep 2019 13:53:13 +0200
Subject: [PATCH] Partial index for namespaces.type

Relates to https://gitlab.com/gitlab-org/gitlab-ce/issues/66956
---
 .../ab-partial-index-for-namespaces-type.yml  |  5 +++++
 ...ude_nulls_from_index_on_namespaces_type.rb | 20 +++++++++++++++++++
 db/schema.rb                                  |  2 +-
 3 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 changelogs/unreleased/ab-partial-index-for-namespaces-type.yml
 create mode 100644 db/migrate/20190910114843_exclude_nulls_from_index_on_namespaces_type.rb

diff --git a/changelogs/unreleased/ab-partial-index-for-namespaces-type.yml b/changelogs/unreleased/ab-partial-index-for-namespaces-type.yml
new file mode 100644
index 00000000000..ad1802d5dce
--- /dev/null
+++ b/changelogs/unreleased/ab-partial-index-for-namespaces-type.yml
@@ -0,0 +1,5 @@
+---
+title: Partial index for namespaces.type
+merge_request: 32876
+author:
+type: performance
diff --git a/db/migrate/20190910114843_exclude_nulls_from_index_on_namespaces_type.rb b/db/migrate/20190910114843_exclude_nulls_from_index_on_namespaces_type.rb
new file mode 100644
index 00000000000..5645e3be5d9
--- /dev/null
+++ b/db/migrate/20190910114843_exclude_nulls_from_index_on_namespaces_type.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+class ExcludeNullsFromIndexOnNamespacesType < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index(:namespaces, :type, where: 'type is not null', name: 'index_namespaces_on_type_partial')
+    remove_concurrent_index_by_name(:namespaces, 'index_namespaces_on_type')
+  end
+
+  def down
+    add_concurrent_index(:namespaces, :type, name: 'index_namespaces_on_type')
+    remove_concurrent_index_by_name(:namespaces, 'index_namespaces_on_type_partial')
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 39faf1e651e..cb124f7deb4 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -2291,7 +2291,7 @@ ActiveRecord::Schema.define(version: 2019_09_12_061145) do
     t.index ["runners_token_encrypted"], name: "index_namespaces_on_runners_token_encrypted", unique: true
     t.index ["shared_runners_minutes_limit", "extra_shared_runners_minutes_limit"], name: "index_namespaces_on_shared_and_extra_runners_minutes_limit"
     t.index ["trial_ends_on"], name: "index_namespaces_on_trial_ends_on", where: "(trial_ends_on IS NOT NULL)"
-    t.index ["type"], name: "index_namespaces_on_type"
+    t.index ["type"], name: "index_namespaces_on_type_partial", where: "(type IS NOT NULL)"
   end
 
   create_table "note_diff_files", id: :serial, force: :cascade do |t|
-- 
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