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| author | Robert Haas <rhaas@postgresql.org> | 2017-09-29 10:20:44 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2017-09-29 10:25:44 -0400 |
| commit | 8b304b8b72b0a60f1968d39f01cf817c8df863ec (patch) | |
| tree | ae476a3b7697ba10e7f9cb8e4dcb552f7632a84a /src/backend/utils/misc/postgresql.conf.sample | |
| parent | d2773f9bcd980cf6ed720928cd0700196608ef19 (diff) | |
| download | postgresql-8b304b8b72b0a60f1968d39f01cf817c8df863ec.tar.gz postgresql-8b304b8b72b0a60f1968d39f01cf817c8df863ec.zip | |
Remove replacement selection sort.
At the time replacement_sort_tuples was introduced, there were still
cases where replacement selection sort noticeably outperformed using
quicksort even for the first run. However, those cases seem to have
evaporated as a result of further improvements made since that time
(and perhaps also advances in CPU technology). So remove replacement
selection and the controlling GUC entirely. This makes tuplesort.c
noticeably simpler and probably paves the way for further
optimizations someone might want to do later.
Peter Geoghegan, with review and testing by Tomas Vondra and me.
Discussion: https://postgr.es/m/CAH2-WzmmNjG_K0R9nqYwMq3zjyJJK+hCbiZYNGhAy-Zyjs64GQ@mail.gmail.com
Diffstat (limited to 'src/backend/utils/misc/postgresql.conf.sample')
| -rw-r--r-- | src/backend/utils/misc/postgresql.conf.sample | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 8ba6b1d08a5..cf4ddcd94a7 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -121,7 +121,6 @@ # you actively intend to use prepared transactions. #work_mem = 4MB # min 64kB #maintenance_work_mem = 64MB # min 1MB -#replacement_sort_tuples = 150000 # limits use of replacement selection sort #autovacuum_work_mem = -1 # min 1MB, or -1 to use maintenance_work_mem #max_stack_depth = 2MB # min 100kB #dynamic_shared_memory_type = posix # the default is the first option |