PERF: Remove redundant post_timings_summary index (#14164)

PERF: Remove redundant post_timings_summary index (#14164)

It’s redundant since post_timings_unique exists which has a superset of the columns with the same prefix.

diff --git a/app/models/post_timing.rb b/app/models/post_timing.rb
index 2670f3d..e272d7f 100644
--- a/app/models/post_timing.rb
+++ b/app/models/post_timing.rb
@@ -225,6 +225,5 @@ end
 # Indexes
 #
 #  index_post_timings_on_user_id  (user_id)
-#  post_timings_summary           (topic_id,post_number)
 #  post_timings_unique            (topic_id,post_number,user_id) UNIQUE
 #
diff --git a/db/migrate/20210824203421_remove_post_timings_summary_index.rb b/db/migrate/20210824203421_remove_post_timings_summary_index.rb
new file mode 100644
index 0000000..856a89e
--- /dev/null
+++ b/db/migrate/20210824203421_remove_post_timings_summary_index.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class RemovePostTimingsSummaryIndex < ActiveRecord::Migration[6.1]
+  def change
+    remove_index :post_timings, column: [:topic_id, :post_number], name: :post_timings_summary, if_exists: true
+  end
+end

GitHub sha: d11f19f09928c2f26d215c357c3f76330323075b

This commit appears in #14164 which was approved by Falco and davidtaylorhq. It was merged by danielwaterworth.