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Use parameterized paths to generate inner indexscans more flexibly.

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This patch fixes the planner so that it can generate nestloop-with-
inner-indexscan plans even with one or more levels of joining between
the indexscan and the nestloop join that is supplying the parameter.
The executor was fixed to handle such cases some time ago, but the
planner was not ready.  This should improve our plans in many situations
where join ordering restrictions formerly forced complete table scans.

There is probably a fair amount of tuning work yet to be done, because
of various heuristics that have been added to limit the number of
parameterized paths considered.  However, we are not going to find out
what needs to be adjusted until the code gets some real-world use, so
it's time to get it in there where it can be tested easily.

Note API change for index AM amcostestimate functions.  I'm not aware of
any non-core index AMs, but if there are any, they will need minor
adjustments.
This commit is contained in:
Tom Lane
2012-01-27 19:26:38 -05:00
parent b376ec6fa5
commit e2fa76d80b
26 changed files with 3884 additions and 2292 deletions
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21
src/include/optimizer/pathnode.h
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@@ -26,6 +26,9 @@ extern int compare_fractional_path_costs(Path *path1, Path *path2,
double fraction);
extern void set_cheapest(RelOptInfo *parent_rel);
extern void add_path(RelOptInfo *parent_rel, Path *new_path);
extern bool add_path_precheck(RelOptInfo *parent_rel,
Cost startup_cost, Cost total_cost,
List *pathkeys, Relids required_outer);
extern Path *create_seqscan_path(PlannerInfo *root, RelOptInfo *rel);
extern IndexPath *create_index_path(PlannerInfo *root,
@@ -37,11 +40,12 @@ extern IndexPath *create_index_path(PlannerInfo *root,
List *pathkeys,
ScanDirection indexscandir,
bool indexonly,
RelOptInfo *outer_rel);
Relids required_outer,
double loop_count);
extern BitmapHeapPath *create_bitmap_heap_path(PlannerInfo *root,
RelOptInfo *rel,
Path *bitmapqual,
RelOptInfo *outer_rel);
double loop_count);
extern BitmapAndPath *create_bitmap_and_path(PlannerInfo *root,
RelOptInfo *rel,
List *bitmapquals);
@@ -66,23 +70,31 @@ extern Path *create_ctescan_path(PlannerInfo *root, RelOptInfo *rel);
extern Path *create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel);
extern ForeignPath *create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel);
extern Relids calc_nestloop_required_outer(Path *outer_path, Path *inner_path);
extern Relids calc_non_nestloop_required_outer(Path *outer_path, Path *inner_path);
extern NestPath *create_nestloop_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
SemiAntiJoinFactors *semifactors,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys);
List *pathkeys,
Relids required_outer);
extern MergePath *create_mergejoin_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys,
Relids required_outer,
List *mergeclauses,
List *outersortkeys,
List *innersortkeys);
@@ -90,10 +102,13 @@ extern MergePath *create_mergejoin_path(PlannerInfo *root,
extern HashPath *create_hashjoin_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
SemiAntiJoinFactors *semifactors,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
Relids required_outer,
List *hashclauses);
/*