1 files changed, 50 insertions, 0 deletions
diff --git a/db/migrate/20171124125748_populate_missing_merge_request_statuses.rb b/db/migrate/20171124125748_populate_missing_merge_request_statuses.rb
new file mode 100644
index 00000000000..72fbab59f4c
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+++ b/db/migrate/20171124125748_populate_missing_merge_request_statuses.rb
@@ -0,0 +1,50 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class PopulateMissingMergeRequestStatuses < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class MergeRequest < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'merge_requests'
+  end
+
+  def up
+    say 'Populating missing merge_requests.state values'
+
+    # GitLab.com has no rows where "state" is NULL, and technically this should
+    # never happen. However it doesn't hurt to be 100% certain.
+    MergeRequest.where(state: nil).each_batch do |batch|
+      batch.update_all(state: 'opened')
+    end
+
+    say 'Populating missing merge_requests.merge_status values. ' \
+      'This will take a few minutes...'
+
+    # GitLab.com has 66 880 rows where "merge_status" is NULL, dating back all
+    # the way to 2011.
+    MergeRequest.where(merge_status: nil).each_batch(of: 10_000) do |batch|
+      batch.update_all(merge_status: 'unchecked')
+
+      # We want to give PostgreSQL some time to vacuum any dead tuples. In
+      # production we see it takes roughly 1 minute for a vacuuming run to clear
+      # out 10-20k dead tuples, so we'll wait for 90 seconds between every
+      # batch.
+      sleep(90) if sleep?
+    end
+  end
+
+  def down
+    # Reverting this makes no sense.
+  end
+
+  def sleep?
+    Rails.env.staging? || Rails.env.production?
+  end
+end