Improve Append/MergeAppend EXPLAIN output when all subplans are pruned.

2019-12-01 01:58:27 Michael Paquier (michael-kun) Closed in commitfest 2019-11 with status: Returned with feedback 2019-09-30 18:53:41 Álvaro Herrera (alvherre) Closed in commitfest 2019-09 with status: Moved to next CF 2019-08-01 23:39:05 Thomas Munro (macdice) Closed in commitfest 2019-07 with status: Moved to next CF 2019-04-29 01:56:25 David Rowley (davidrowley) Attached mail thread 001001d4f44b$2a2cca50$7e865ef0$@lab.ntt.co.jp 2019-04-29 01:55:48 David Rowley (davidrowley) Detached mail thread CAKJS1f_1c260nOt_vBJ067AZ3JXptXVRohDVMLEBmudX1YEx-A@mail.gmail.com 2019-04-23 23:41:13 David Rowley (davidrowley) Changed authors to David Rowley (davidrowley) 2019-04-23 23:40:49 David Rowley (davidrowley) Attached mail thread CAKJS1f_1c260nOt_vBJ067AZ3JXptXVRohDVMLEBmudX1YEx-A@mail.gmail.com 2019-04-23 23:40:49 David Rowley (davidrowley) Created patch record