Consider Parallel Append of partial paths for UNION [ALL]. Without this patch, we can implement a UNION or UNION ALL as an Append where Gather appears beneath one or more of the Append branches, but this lets us put the Gather node on top, with a partial path for each relation underneath.
There is considerably more work that could be done to improve planning in this area, but that will probably need to wait for a future release. Patch by me, reviewed and tested by Ashutosh Bapat and Rajkumar Raghuwanshi. Discussion: http://postgr.es/m/CA+TgmoaLRAOqHmMZx=esm3vdepceg+-xxzsrxq8gtfjo_zb...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/88ba0ae2aa4aaba8ea0d85c0ff81cc46912d9308 Modified Files -------------- src/backend/optimizer/prep/prepunion.c | 93 +++++++++++++++++++++++++++++++++- 1 file changed, 91 insertions(+), 2 deletions(-)
