git.postgresql.org Git - postgresql.git/commitdiff

git projects / postgresql.git / commitdiff

Adjust reltarget assignment for UPPERREL_PARTIAL_DISTINCT rel

author David Rowley <drowley@postgresql.org>

Wed, 7 Feb 2024 08:22:34 +0000 (21:22 +1300)

committer David Rowley <drowley@postgresql.org>

Wed, 7 Feb 2024 08:22:34 +0000 (21:22 +1300)

A comment in grouping_planner() claimed that the PlannerInfo
upper_targets array was not used in core code. However, the code that
generated the paths for the UPPERREL_PARTIAL_DISTINCT rel made that
comment untrue.

Here we adjust the create_distinct_paths() function signature to pass
down the PathTarget the same as is done for create_grouping_paths(),
thus making the aforementioned comment true again.

In passing adjust the order of the upper_targets[] assignments. These
seem to be following the reverse enum order apart from
UPPERREL_PARTIAL_DISTINCT.

Also, update the header comment for generate_gather_paths() to mention
the function is also used to create gather paths for partial distinct
paths.

Author: Richard Guo, David Rowley
Discussion: https://postgr.es/m/CAMbWs48u9VoVOouJsys1qOaC9WVGVmBa+wT1dx8KvxF5GPzezA@mail.gmail.com

src/backend/optimizer/path/allpaths.c patch | blob | blame | history

src/backend/optimizer/plan/planner.c patch | blob | blame | history

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c

index 84c4de488a6352f33c0ca2287f818c7ce4731e28..d404fbf262c218600237746088ece7b6266d1580 100644 (file)

--- a/src/backend/optimizer/path/allpaths.c

+++ b/src/backend/optimizer/path/allpaths.c

@@ -3053,10 +3053,10 @@ set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)

* If we're generating paths for a scan or join relation, override_rows will

* be false, and we'll just use the relation's size estimate. When we're

- * being called for a partially-grouped path, though, we need to override

- * the rowcount estimate. (It's not clear that the particular value we're

- * using here is actually best, but the underlying rel has no estimate so

- * we must do something.)

+ * being called for a partially-grouped or partially-distinct path, though, we

+ * need to override the rowcount estimate. (It's not clear that the

+ * particular value we're using here is actually best, but the underlying rel

+ * has no estimate so we must do something.)

void

generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c

index acc324122fde92f409c678010b1ad83672cab68c..be4e182869a19f648aae55c3161a3d4444abf72a 100644 (file)

--- a/src/backend/optimizer/plan/planner.c

+++ b/src/backend/optimizer/plan/planner.c

@@ -190,10 +190,12 @@ static void create_one_window_path(PlannerInfo *root,

WindowFuncLists *wflists,

List *activeWindows);

static RelOptInfo *create_distinct_paths(PlannerInfo *root,

- RelOptInfo *input_rel);

+ RelOptInfo *input_rel,

+ PathTarget *target);

static void create_partial_distinct_paths(PlannerInfo *root,

RelOptInfo *input_rel,

- RelOptInfo *final_distinct_rel);

+ RelOptInfo *final_distinct_rel,

+ PathTarget *target);

static RelOptInfo *create_final_distinct_paths(PlannerInfo *root,

RelOptInfo *input_rel,

RelOptInfo *distinct_rel);

@@ -1644,8 +1646,8 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)

root->upper_targets[UPPERREL_FINAL] = final_target;

root->upper_targets[UPPERREL_ORDERED] = final_target;

- root->upper_targets[UPPERREL_PARTIAL_DISTINCT] = sort_input_target;

root->upper_targets[UPPERREL_DISTINCT] = sort_input_target;

+ root->upper_targets[UPPERREL_PARTIAL_DISTINCT] = sort_input_target;

root->upper_targets[UPPERREL_WINDOW] = sort_input_target;

root->upper_targets[UPPERREL_GROUP_AGG] = grouping_target;

@@ -1695,7 +1697,8 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)

if (parse->distinctClause)

{

current_rel = create_distinct_paths(root,

- current_rel);

+ current_rel,

+ sort_input_target);

}

} /* end of if (setOperations) */

@@ -4568,12 +4571,14 @@ create_one_window_path(PlannerInfo *root,

* Build a new upperrel containing Paths for SELECT DISTINCT evaluation.

* input_rel: contains the source-data Paths

+ * target: the pathtarget for the result Paths to compute

* Note: input paths should already compute the desired pathtarget, since

* Sort/Unique won't project anything.

static RelOptInfo *

-create_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel)

+create_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,

+ PathTarget *target)

{

RelOptInfo *distinct_rel;

@@ -4601,7 +4606,7 @@ create_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel)

create_final_distinct_paths(root, input_rel, distinct_rel);

/* now build distinct paths based on input_rel's partial_pathlist */

- create_partial_distinct_paths(root, input_rel, distinct_rel);

+ create_partial_distinct_paths(root, input_rel, distinct_rel, target);

/* Give a helpful error if we failed to create any paths */

if (distinct_rel->pathlist == NIL)

@@ -4643,7 +4648,8 @@ create_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel)

static void

create_partial_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,

- RelOptInfo *final_distinct_rel)

+ RelOptInfo *final_distinct_rel,

+ PathTarget *target)

{

RelOptInfo *partial_distinct_rel;

Query *parse;

@@ -4664,7 +4670,7 @@ create_partial_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,

partial_distinct_rel = fetch_upper_rel(root, UPPERREL_PARTIAL_DISTINCT,

NULL);

- partial_distinct_rel->reltarget = root->upper_targets[UPPERREL_PARTIAL_DISTINCT];

+ partial_distinct_rel->reltarget = target;

partial_distinct_rel->consider_parallel = input_rel->consider_parallel;

This is the main PostgreSQL git repository.

RSS Atom