Thread: [COMMITTERS] pgsql: Fix regression in parallel planning against inheritance tables.
[COMMITTERS] pgsql: Fix regression in parallel planning against inheritance tables.
From
Robert Haas
Date:
Fix regression in parallel planning against inheritance tables. Commit 51ee6f3160d2e1515ed6197594bda67eb99dc2cc accidentally changed the behavior around inheritance hierarchies; before, we always considered parallel paths even for very small inheritance children, because otherwise an inheritance hierarchy with even one small child wouldn't be eligible for parallelism. That exception was inadverently removed; put it back. In passing, also adjust the degree-of-parallelism comptuation for index-only scans not to consider the number of heap pages fetched. Otherwise, we'll avoid parallel index-only scans on tables that are mostly all-visible, which isn't especially logical. Robert Haas and Amit Kapila, per a report from Ashutosh Sharma. Discussion: http://postgr.es/m/CAE9k0PmgSoOHRd60SHu09aRVTHRSs8s6pmyhJKWHxWw9C_x+XA@mail.gmail.com Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/2609e91fcf9dcf36af40cd0c5b755dccf6057df6 Modified Files -------------- src/backend/optimizer/path/allpaths.c | 46 +++++++++++++++++++---------------- src/backend/optimizer/path/costsize.c | 11 +++++++-- src/include/optimizer/paths.h | 4 +-- 3 files changed, 36 insertions(+), 25 deletions(-)