don't create storage when unnecessary

When Who What
2019-01-04 11:32:31 Peter Eisentraut (petere) Closed in commitfest 2019-01 with status: Committed
2019-01-04 11:32:31 Peter Eisentraut (petere) Changed committer to alvherre
2018-12-26 04:52:46 Michael Paquier (michael-kun) New status: Waiting on Author
2018-12-06 21:56:46 Álvaro Herrera (alvherre) Changed authors to Álvaro Herrera (alvherre)
2018-12-06 21:56:39 Álvaro Herrera (alvherre) Attached mail thread 20181206215552.fm2ypuxq6nhpwjuc@alvherre.pgsql
2018-12-06 21:56:39 Álvaro Herrera (alvherre) Created patch record