1 files changed, 37 insertions, 0 deletions
diff --git a/db/migrate/20171106155656_turn_issues_due_date_index_to_partial_index.rb b/db/migrate/20171106155656_turn_issues_due_date_index_to_partial_index.rb
new file mode 100644
index 00000000000..e4bed778695
--- /dev/null
+++ b/db/migrate/20171106155656_turn_issues_due_date_index_to_partial_index.rb
@@ -0,0 +1,37 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class TurnIssuesDueDateIndexToPartialIndex < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  NEW_INDEX_NAME = 'idx_issues_on_project_id_and_due_date_and_id_and_state_partial'
+  OLD_INDEX_NAME = 'index_issues_on_project_id_and_due_date_and_id_and_state'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index(
+      :issues,
+      [:project_id, :due_date, :id, :state],
+      where: 'due_date IS NOT NULL',
+      name: NEW_INDEX_NAME
+    )
+
+    # We set the column name to nil as otherwise Rails will ignore the custom
+    # index name and remove the wrong index.
+    remove_concurrent_index(:issues, nil, name: OLD_INDEX_NAME)
+  end
+
+  def down
+    add_concurrent_index(
+      :issues,
+      [:project_id, :due_date, :id, :state],
+      name: OLD_INDEX_NAME
+    )
+
+    remove_concurrent_index(:issues, nil, name: NEW_INDEX_NAME)
+  end
+end