1 files changed, 28 insertions, 9 deletions

diff --git a/lib/gitlab/cycle_analytics/plan_event_fetcher.rb b/lib/gitlab/cycle_analytics/plan_event_fetcher.rb
index 7d342a2d2cb..b260822788d 100644
--- a/lib/gitlab/cycle_analytics/plan_event_fetcher.rb
+++ b/lib/gitlab/cycle_analytics/plan_event_fetcher.rb
@@ -2,40 +2,59 @@ module Gitlab
   module CycleAnalytics
     class PlanEventFetcher < BaseEventFetcher
       def initialize(*args)
-        @projections = [mr_diff_table[:st_commits].as('commits'),
+        @projections = [mr_diff_table[:id],
+                        mr_diff_table[:st_commits],
                         issue_metrics_table[:first_mentioned_in_commit_at]]
 
         super(*args)
       end
 
       def events_query
-        base_query.join(mr_diff_table).on(mr_diff_table[:merge_request_id].eq(mr_table[:id]))
+        base_query
+          .join(mr_diff_table)
+          .on(mr_diff_table[:merge_request_id].eq(mr_table[:id]))
 
         super
       end
 
       private
 
+      def merge_request_diff_commits
+        @merge_request_diff_commits ||=
+          MergeRequestDiffCommit
+            .where(merge_request_diff_id: event_result.map { |event| event['id'] })
+            .group_by(&:merge_request_diff_id)
+      end
+
       def serialize(event)
-        st_commit = first_time_reference_commit(event.delete('commits'), event)
+        commit = first_time_reference_commit(event)
 
-        return unless st_commit
+        return unless commit
 
-        serialize_commit(event, st_commit, query)
+        serialize_commit(event, commit, query)
       end
 
-      def first_time_reference_commit(commits, event)
+      def first_time_reference_commit(event)
+        return nil unless event && merge_request_diff_commits
+
+        commits =
+          if event['st_commits'].present?
+            YAML.load(event['st_commits'])
+          else
+            merge_request_diff_commits[event['id'].to_i]
+          end
+
         return nil if commits.blank?
 
-        YAML.load(commits).find do |commit|
+        commits.find do |commit|
           next unless commit[:committed_date] && event['first_mentioned_in_commit_at']
 
           commit[:committed_date].to_i == DateTime.parse(event['first_mentioned_in_commit_at'].to_s).to_i
         end
       end
 
-      def serialize_commit(event, st_commit, query)
-        commit = Commit.new(Gitlab::Git::Commit.new(st_commit), @project)
+      def serialize_commit(event, commit, query)
+        commit = Commit.new(Gitlab::Git::Commit.new(commit.to_hash), @project)
 
         AnalyticsCommitSerializer.new(project: @project, total_time: event['total_time']).represent(commit)
       end