1 files changed, 40 insertions, 0 deletions
diff --git a/db/post_migrate/20220315181136_backfill_work_item_type_id_on_issues.rb b/db/post_migrate/20220315181136_backfill_work_item_type_id_on_issues.rb
new file mode 100644
index 00000000000..8838a27f233
--- /dev/null
+++ b/db/post_migrate/20220315181136_backfill_work_item_type_id_on_issues.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class BackfillWorkItemTypeIdOnIssues < Gitlab::Database::Migration[1.0]
+  MIGRATION = 'BackfillWorkItemTypeIdForIssues'
+  BATCH_CLASS_NAME = 'BackfillIssueWorkItemTypeBatchingStrategy'
+  BATCH_SIZE = 10_000
+  MAX_BATCH_SIZE = 30_000
+  SUB_BATCH_SIZE = 100
+  INTERVAL = 2.minutes
+
+  class MigrationWorkItemType < ApplicationRecord
+    self.table_name = 'work_item_types'
+
+    def self.id_by_type
+      where(namespace_id: nil).order(:base_type).pluck(:base_type, :id).to_h
+    end
+  end
+
+  def up
+    # We expect no more than 5 types. Only 3 of them are expected to have associated issues at the moment
+    MigrationWorkItemType.id_by_type.each do |base_type, type_id|
+      queue_batched_background_migration(
+        MIGRATION,
+        :issues,
+        :id,
+        base_type,
+        type_id,
+        job_interval: INTERVAL,
+        batch_size: BATCH_SIZE,
+        max_batch_size: MAX_BATCH_SIZE,
+        sub_batch_size: SUB_BATCH_SIZE,
+        batch_class_name: BATCH_CLASS_NAME
+      )
+    end
+  end
+
+  def down
+    Gitlab::Database::BackgroundMigration::BatchedMigration.where(job_class_name: MIGRATION).delete_all
+  end
+end