db: add reason index on post_flags, post_appeals.

db/migrate/20170416224142_add_reason_ts_vector_index_to_post_flags_and_appeals.rb

@@ -0,0 +1,13 @@
+class AddReasonTsVectorIndexToPostFlagsAndAppeals < ActiveRecord::Migration
+  def up
+    execute "SET statement_timeout = 0"
+    execute "CREATE INDEX index_post_flags_on_reason_tsvector ON post_flags USING gin (to_tsvector('pg_catalog.english', reason))"
+    execute "CREATE INDEX index_post_appeals_on_reason_tsvector ON post_appeals USING gin (to_tsvector('pg_catalog.english', reason))"
+  end
+
+  def down
+    execute "SET statement_timeout = 0"
+    remove_index :post_flags, name: "index_post_flags_on_reason_tsvector"
+    remove_index :post_appeals, name: "index_post_appeals_on_reason_tsvector"
+  end
+end