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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-06-16 13:47:20 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-06-16 13:47:20 -0400 |
| commit | 75be66464cb1bffa1e5757907b9a04ad5afc7859 (patch) | |
| tree | 71d51f8b6e3ba127480cf6165b4b2c165c2fea0f /src/backend/utils/misc/postgresql.conf.sample | |
| parent | 3b5a2a8856b810ed354fb6dbb7df8d7325ece82f (diff) | |
Invent min_parallel_relation_size GUC to replace a hard-wired constant.
The main point of doing this is to allow the cutoff to be set very small,
even zero, to allow parallel-query behavior to be tested on relatively
small tables such as we typically use in the regression tests. But it
might be of use to users too. The number-of-workers scaling behavior in
create_plain_partial_paths() is pretty ad-hoc and subject to change, so
we won't expose anything about that, but the notion of not considering
parallel query at all for tables below size X seems reasonably stable.
Amit Kapila, per a suggestion from me
Discussion: <17170.1465830165@sss.pgh.pa.us>
Diffstat (limited to 'src/backend/utils/misc/postgresql.conf.sample')
| -rw-r--r-- | src/backend/utils/misc/postgresql.conf.sample | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 8260e371bc9..3fa05403bbc 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -304,6 +304,7 @@ #cpu_operator_cost = 0.0025 # same scale as above #parallel_tuple_cost = 0.1 # same scale as above #parallel_setup_cost = 1000.0 # same scale as above +#min_parallel_relation_size = 8MB #effective_cache_size = 4GB # - Genetic Query Optimizer - |