1 files changed, 43 insertions, 0 deletions
diff --git a/db/migrate/20170803130232_reorganise_issues_indexes_for_faster_sorting.rb b/db/migrate/20170803130232_reorganise_issues_indexes_for_faster_sorting.rb
new file mode 100644
index 00000000000..eb7d1be1732
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+++ b/db/migrate/20170803130232_reorganise_issues_indexes_for_faster_sorting.rb
@@ -0,0 +1,43 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class ReorganiseIssuesIndexesForFasterSorting < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  REMOVE_INDEX_COLUMNS = %i[project_id created_at due_date updated_at].freeze
+
+  ADD_INDEX_COLUMNS = [
+    %i[project_id created_at id state],
+    %i[project_id due_date id state],
+    %i[project_id updated_at id state]
+  ].freeze
+
+  TABLE = :issues
+
+  def up
+    add_indexes(ADD_INDEX_COLUMNS)
+    remove_indexes(REMOVE_INDEX_COLUMNS)
+  end
+
+  def down
+    add_indexes(REMOVE_INDEX_COLUMNS)
+    remove_indexes(ADD_INDEX_COLUMNS)
+  end
+
+  def add_indexes(columns)
+    columns.each do |column|
+      add_concurrent_index(TABLE, column) unless index_exists?(TABLE, column)
+    end
+  end
+
+  def remove_indexes(columns)
+    columns.each do |column|
+      remove_concurrent_index(TABLE, column) if index_exists?(TABLE, column)
+    end
+  end
+end