From d91a823836f416dc0bdf0fe8527695d372dcb347 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Sat, 22 Apr 2023 16:14:56 +0000
Subject: [PATCH 1/3] Remove unused indexes

These indexes were always listed as unused and several grow quite large.
The most significant impact is the activities_visibility_index which takes many hours to rebuild when restoring the server from backup even on fast hardware.
---
 .../20230422154018_drop_unused_indexes.exs    | 88 +++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 priv/repo/migrations/20230422154018_drop_unused_indexes.exs

diff --git a/priv/repo/migrations/20230422154018_drop_unused_indexes.exs b/priv/repo/migrations/20230422154018_drop_unused_indexes.exs
new file mode 100644
index 000000000..f2ba6b8df
--- /dev/null
+++ b/priv/repo/migrations/20230422154018_drop_unused_indexes.exs
@@ -0,0 +1,88 @@
+defmodule Pleroma.Repo.Migrations.DropUnusedIndexes do
+  use Ecto.Migration
+
+  @disable_ddl_transaction true
+  @disable_migration_lock true
+
+  def up do
+    drop_if_exists(
+      index(:activities, ["(data->>'actor')", "inserted_at desc"], name: :activities_actor_index)
+    )
+
+    drop_if_exists(index(:activities, ["(data->'to')"], name: :activities_to_index))
+
+    drop_if_exists(index(:activities, ["(data->'cc')"], name: :activities_cc_index))
+
+    drop_if_exists(index(:activities, ["(split_part(actor, '/', 3))"], name: :activities_hosts))
+
+    drop_if_exists(
+      index(:activities, ["(data->'object'->>'inReplyTo')"], name: :activities_in_reply_to)
+    )
+
+    drop_if_exists(
+      index(:activities, ["((data #> '{\"object\",\"likes\"}'))"], name: :activities_likes)
+    )
+
+    drop_if_exists(
+      index(:activities, ["activity_visibility(actor, recipients, data)", "id DESC NULLS LAST"],
+        name: :activities_visibility_index,
+        where: "data->>'type' = 'Create'"
+      )
+    )
+  end
+
+  def down do
+    create_if_not_exists(
+      index(:activities, ["(data->>'actor')", "inserted_at desc"],
+        name: :activities_actor_index,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["(data->'to')"],
+        name: :activities_to_index,
+        using: :gin,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["(data->'cc')"],
+        name: :activities_cc_index,
+        using: :gin,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["(split_part(actor, '/', 3))"],
+        name: :activities_hosts,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["(data->'object'->>'inReplyTo')"],
+        name: :activities_in_reply_to,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["((data #> '{\"object\",\"likes\"}'))"],
+        name: :activities_likes,
+        using: :gin,
+        concurrently: true
+      )
+    )
+
+    create_if_not_exists(
+      index(:activities, ["activity_visibility(actor, recipients, data)", "id DESC NULLS LAST"],
+        name: :activities_visibility_index,
+        where: "data->>'type' = 'Create'",
+        concurrently: true
+      )
+    )
+  end
+end

From 10dfa107d5d5d3b6fa7c13eb005c4cd5b6b94661 Mon Sep 17 00:00:00 2001
From: Lain Soykaf <lain@lain.com>
Date: Sun, 11 Jun 2023 16:22:03 +0400
Subject: [PATCH 2/3] Update changelog

---
 changelog.d/3874.remove | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/3874.remove

diff --git a/changelog.d/3874.remove b/changelog.d/3874.remove
new file mode 100644
index 000000000..a81f744bf
--- /dev/null
+++ b/changelog.d/3874.remove
@@ -0,0 +1 @@
+Remove a few unused indexes.

From 22878cf84afd3f8b844c66e99f37022318c4c55e Mon Sep 17 00:00:00 2001
From: Lain Soykaf <lain@lain.com>
Date: Sun, 11 Jun 2023 16:22:16 +0400
Subject: [PATCH 3/3] B Migrations: Don't remove activity_visibility_index for
 now.

---
 .../20230422154018_drop_unused_indexes.exs        | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/priv/repo/migrations/20230422154018_drop_unused_indexes.exs b/priv/repo/migrations/20230422154018_drop_unused_indexes.exs
index f2ba6b8df..0d877a798 100644
--- a/priv/repo/migrations/20230422154018_drop_unused_indexes.exs
+++ b/priv/repo/migrations/20230422154018_drop_unused_indexes.exs
@@ -22,13 +22,6 @@ defmodule Pleroma.Repo.Migrations.DropUnusedIndexes do
     drop_if_exists(
       index(:activities, ["((data #> '{\"object\",\"likes\"}'))"], name: :activities_likes)
     )
-
-    drop_if_exists(
-      index(:activities, ["activity_visibility(actor, recipients, data)", "id DESC NULLS LAST"],
-        name: :activities_visibility_index,
-        where: "data->>'type' = 'Create'"
-      )
-    )
   end
 
   def down do
@@ -76,13 +69,5 @@ defmodule Pleroma.Repo.Migrations.DropUnusedIndexes do
         concurrently: true
       )
     )
-
-    create_if_not_exists(
-      index(:activities, ["activity_visibility(actor, recipients, data)", "id DESC NULLS LAST"],
-        name: :activities_visibility_index,
-        where: "data->>'type' = 'Create'",
-        concurrently: true
-      )
-    )
   end
 end