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Diffstat (limited to 'src/backend/optimizer/path/costsize.c')
| -rw-r--r-- | src/backend/optimizer/path/costsize.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index 3eaed5af7a5..627e3f1b954 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -860,6 +860,7 @@ cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel, QualCost qpqual_cost; Cost cpu_per_tuple; Cost cost_per_page; + Cost cpu_run_cost; double tuples_fetched; double pages_fetched; double spc_seq_page_cost, @@ -921,8 +922,21 @@ cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel, startup_cost += qpqual_cost.startup; cpu_per_tuple = cpu_tuple_cost + qpqual_cost.per_tuple; + cpu_run_cost = cpu_per_tuple * tuples_fetched; + + /* Adjust costing for parallelism, if used. */ + if (path->parallel_workers > 0) + { + double parallel_divisor = get_parallel_divisor(path); + + /* The CPU cost is divided among all the workers. */ + cpu_run_cost /= parallel_divisor; - run_cost += cpu_per_tuple * tuples_fetched; + path->rows = clamp_row_est(path->rows / parallel_divisor); + } + + + run_cost += cpu_run_cost; /* tlist eval costs are paid per output row, not per tuple scanned */ startup_cost += path->pathtarget->cost.startup; |