Merge branch 'rum-index' into 'develop'

Search: Use RUM index.

See merge request pleroma/pleroma!1136

.gitlab-ci.yml

@@ -45,7 +45,8 @@ docs-build:
 unit-testing:
   stage: test
   services:
-  - name: postgres:9.6.2
+  - name: lainsoykaf/postgres-with-rum
+    alias: postgres
     command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
   script:
     - mix deps.get
@@ -54,6 +55,21 @@ unit-testing:
     - mix test --trace --preload-modules
     - mix coveralls
 
+unit-testing-rum:
+  stage: test
+  services:
+  - name: lainsoykaf/postgres-with-rum
+    alias: postgres
+    command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
+  variables:
+    RUM_ENABLED: "true"
+  script:
+    - mix deps.get
+    - mix ecto.create
+    - mix ecto.migrate
+    - "mix ecto.migrate --migrations-path priv/repo/optional_migrations/rum_indexing/"
+    - mix test --trace --preload-modules
+
 lint:
   stage: test
   script:
@@ -65,7 +81,6 @@ analysis:
     - mix deps.get
     - mix credo --strict --only=warnings,todo,fixme,consistency,readability
 
-
 docs-deploy:
   stage: deploy
   image: alpine:3.9

config/config.exs

@@ -465,6 +465,8 @@ config :pleroma, :oauth2,
   token_expires_in: 600,
   issue_new_refresh_token: true
 
+config :pleroma, :database, rum_enabled: false
+
 config :http_signatures,
   adapter: Pleroma.Signature
 

config/test.exs

@@ -63,6 +63,10 @@ config :pleroma, :app_account_creation, max_requests: 5
 
 config :pleroma, :http_security, report_uri: "https://endpoint.com"
 
+rum_enabled = System.get_env("RUM_ENABLED") == "true"
+config :pleroma, :database, rum_enabled: rum_enabled
+IO.puts("RUM enabled: #{rum_enabled}")
+
 try do
   import_config "test.secret.exs"
 rescue

docs/config.md

@@ -544,3 +544,18 @@ Configure OAuth 2 provider capabilities:
 * `shortcode_globs`: Location of custom emoji files. `*` can be used as a wildcard. Example `["/emoji/custom/**/*.png"]`
 * `groups`: Emojis are ordered in groups (tags). This is an array of key-value pairs where the key is the groupname and the value the location or array of locations. `*` can be used as a wildcard. Example `[Custom: ["/emoji/*.png", "/emoji/custom/*.png"]]`
 * `default_manifest`: Location of the JSON-manifest. This manifest contains information about the emoji-packs you can download. Currently only one manifest can be added (no arrays).
+
+## Database options
+
+### RUM indexing for full text search
+* `rum_enabled`: If RUM indexes should be used. Defaults to `false`.
+
+RUM indexes are an alternative indexing scheme that is not included in PostgreSQL by default. While they may eventually be mainlined, for now they have to be installed as a PostgreSQL extension from https://github.com/postgrespro/rum.
+
+Their advantage over the standard GIN indexes is that they allow efficient ordering of search results by timestamp, which makes search queries a lot faster on larger servers, by one or two orders of magnitude. They take up around 3 times as much space as GIN indexes.
+
+To enable them, both the `rum_enabled` flag has to be set and the following special migration has to be run:
+
+`mix ecto.migrate --migrations-path priv/repo/optional_migrations/rum_indexing/`
+
+This will probably take a long time.

lib/pleroma/web/mastodon_api/mastodon_api_controller.ex

@@ -1009,6 +1009,30 @@ defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
     end
   end
 
+  def status_search_query_with_gin(q, query) do
+    from([a, o] in q,
+      where:
+        fragment(
+          "to_tsvector('english', ?->>'content') @@ plainto_tsquery('english', ?)",
+          o.data,
+          ^query
+        ),
+      order_by: [desc: :id]
+    )
+  end
+
+  def status_search_query_with_rum(q, query) do
+    from([a, o] in q,
+      where:
+        fragment(
+          "? @@ plainto_tsquery('english', ?)",
+          o.fts_content,
+          ^query
+        ),
+      order_by: [fragment("? <=> now()::date", o.inserted_at)]
+    )
+  end
+
   def status_search(user, query) do
     fetched =
       if Regex.match?(~r/https?:/, query) do
@@ -1022,20 +1046,19 @@ defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
       end || []
 
     q =
-      from(
-        [a, o] in Activity.with_preloaded_object(Activity),
+      from([a, o] in Activity.with_preloaded_object(Activity),
         where: fragment("?->>'type' = 'Create'", a.data),
         where: "https://www.w3.org/ns/activitystreams#Public" in a.recipients,
-        where:
-          fragment(
-            "to_tsvector('english', ?->>'content') @@ plainto_tsquery('english', ?)",
-            o.data,
-            ^query
-          ),
-        limit: 20,
-        order_by: [desc: :id]
+        limit: 20
       )
 
+    q =
+      if Pleroma.Config.get([:database, :rum_enabled]) do
+        status_search_query_with_rum(q, query)
+      else
+        status_search_query_with_gin(q, query)
+      end
+
     Repo.all(q) ++ fetched
   end
 

priv/repo/optional_migrations/rum_indexing/20190510135645_add_fts_index_to_objects_two.exs

@@ -0,0 +1,34 @@
+defmodule Pleroma.Repo.Migrations.AddFtsIndexToObjectsTwo do
+  use Ecto.Migration
+
+  def up do
+    execute("create extension if not exists rum")
+    drop_if_exists index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
+    alter table(:objects) do
+      add(:fts_content, :tsvector)
+    end
+
+    execute("CREATE FUNCTION objects_fts_update() RETURNS trigger AS $$
+    begin
+      new.fts_content := to_tsvector('english', new.data->>'content');
+      return new;
+    end
+    $$ LANGUAGE plpgsql")
+    execute("create index objects_fts on objects using RUM (fts_content rum_tsvector_addon_ops, inserted_at) with (attach = 'inserted_at', to = 'fts_content');")
+
+    execute("CREATE TRIGGER tsvectorupdate BEFORE INSERT OR UPDATE ON objects
+    FOR EACH ROW EXECUTE PROCEDURE objects_fts_update()")
+
+    execute("UPDATE objects SET updated_at = NOW()")
+  end
+
+  def down do
+    execute "drop index objects_fts"
+    execute "drop trigger tsvectorupdate on objects"
+    execute "drop function objects_fts_update()"
+    alter table(:objects) do
+      remove(:fts_content, :tsvector)
+    end
+    create index(:objects, ["(to_tsvector('english', data->>'content'))"], using: :gin, name: :objects_fts)
+  end
+end