diff options
| author | Simon Riggs | 2015-05-15 18:37:10 +0000 |
|---|---|---|
| committer | Simon Riggs | 2015-05-15 18:37:10 +0000 |
| commit | f6d208d6e51810c73f0e02c477984a6b44627f11 (patch) | |
| tree | 99d540d0b7bda73ff60479f15444f554403d4679 /src/include/optimizer | |
| parent | 11a83bbedd73800db70f6f2af5a8eb10d15d39d7 (diff) | |
TABLESAMPLE, SQL Standard and extensible
Add a TABLESAMPLE clause to SELECT statements that allows
user to specify random BERNOULLI sampling or block level
SYSTEM sampling. Implementation allows for extensible
sampling functions to be written, using a standard API.
Basic version follows SQLStandard exactly. Usable
concrete use cases for the sampling API follow in later
commits.
Petr Jelinek
Reviewed by Michael Paquier and Simon Riggs
Diffstat (limited to 'src/include/optimizer')
| -rw-r--r-- | src/include/optimizer/cost.h | 1 | ||||
| -rw-r--r-- | src/include/optimizer/pathnode.h | 2 |
2 files changed, 3 insertions, 0 deletions
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h index 9c2000b15aa..24003ae3591 100644 --- a/src/include/optimizer/cost.h +++ b/src/include/optimizer/cost.h @@ -68,6 +68,7 @@ extern double index_pages_fetched(double tuples_fetched, BlockNumber pages, double index_pages, PlannerInfo *root); extern void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info); +extern void cost_samplescan(Path *path, PlannerInfo *root, RelOptInfo *baserel); extern void cost_index(IndexPath *path, PlannerInfo *root, double loop_count); extern void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel, diff --git a/src/include/optimizer/pathnode.h b/src/include/optimizer/pathnode.h index 9923f0eb3ea..89c8deda95c 100644 --- a/src/include/optimizer/pathnode.h +++ b/src/include/optimizer/pathnode.h @@ -32,6 +32,8 @@ extern bool add_path_precheck(RelOptInfo *parent_rel, extern Path *create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer); +extern Path *create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, + Relids required_outer); extern IndexPath *create_index_path(PlannerInfo *root, IndexOptInfo *index, List *indexclauses, |