add missing indices on crawls

CHANGELOG.md

@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Added missing indices on crawls and crawl_interactions tables.
+
 ### Security
 
 ## [2.6.0 - 2019-08-10]

backend/priv/repo/migrations/20190810123317_add_crawls_index.exs

@@ -0,0 +1,9 @@
+defmodule Backend.Repo.Migrations.AddCrawlsIndex do
+  use Ecto.Migration
+
+  def change do
+    create index(:crawls, [:instance_domain])
+    create index(:crawl_interactions, [:source_domain])
+    create index(:crawl_interactions, [:target_domain])
+  end
+end