#define EXPRKIND_TABLEFUNC 11
#define EXPRKIND_TABLEFUNC_LATERAL 12
-/* Passthrough data for standard_qp_callback */
-typedef struct
-{
- List *activeWindows; /* active windows, if any */
- List *groupClause; /* overrides parse->groupClause */
-} standard_qp_extra;
-
/*
* Data specific to grouping sets
*/
-
typedef struct
{
List *rollups;
* clauses per Window */
} WindowClauseSortData;
+/* Passthrough data for standard_qp_callback */
+typedef struct
+{
+ List *activeWindows; /* active windows, if any */
+ grouping_sets_data *gset_data; /* grouping sets data, if any */
+} standard_qp_extra;
+
/* Local functions */
static Node *preprocess_expression(PlannerInfo *root, Node *expr, int kind);
static void preprocess_qual_conditions(PlannerInfo *root, Node *jtnode);
root->rowMarks = NIL;
memset(root->upper_rels, 0, sizeof(root->upper_rels));
memset(root->upper_targets, 0, sizeof(root->upper_targets));
+ root->processed_groupClause = NIL;
+ root->processed_distinctClause = NIL;
root->processed_tlist = NIL;
root->update_colnos = NIL;
root->grouping_map = NULL;
}
parse->havingQual = (Node *) newHaving;
- /* Remove any redundant GROUP BY columns */
- remove_useless_groupby_columns(root);
-
/*
* If we have any outer joins, try to reduce them to plain inner joins.
* This step is most easily done after we've done expression
{
gset_data = preprocess_grouping_sets(root);
}
- else
+ else if (parse->groupClause)
{
/* Preprocess regular GROUP BY clause, if any */
- if (parse->groupClause)
- parse->groupClause = preprocess_groupclause(root, NIL);
+ root->processed_groupClause = preprocess_groupclause(root, NIL);
+ /* Remove any redundant GROUP BY columns */
+ remove_useless_groupby_columns(root);
}
/*
/* Set up data needed by standard_qp_callback */
qp_extra.activeWindows = activeWindows;
- qp_extra.groupClause = (gset_data
- ? (gset_data->rollups ? linitial_node(RollupData, gset_data->rollups)->groupClause : NIL)
- : parse->groupClause);
+ qp_extra.gset_data = gset_data;
/*
* Generate the best unsorted and presorted paths for the scan/join
gd->unsortable_refs = NULL;
gd->unsortable_sets = NIL;
+ /*
+ * We don't currently make any attempt to optimize the groupClause when
+ * there are grouping sets, so just duplicate it in processed_groupClause.
+ */
+ root->processed_groupClause = parse->groupClause;
+
if (parse->groupClause)
{
ListCell *lc;
int relid;
/* No chance to do anything if there are less than two GROUP BY items */
- if (list_length(parse->groupClause) < 2)
+ if (list_length(root->processed_groupClause) < 2)
return;
/* Don't fiddle with the GROUP BY clause if the query has grouping sets */
*/
groupbyattnos = (Bitmapset **) palloc0(sizeof(Bitmapset *) *
(list_length(parse->rtable) + 1));
- foreach(lc, parse->groupClause)
+ foreach(lc, root->processed_groupClause)
{
SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
{
List *new_groupby = NIL;
- foreach(lc, parse->groupClause)
+ foreach(lc, root->processed_groupClause)
{
SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
new_groupby = lappend(new_groupby, sgc);
}
- parse->groupClause = new_groupby;
+ root->processed_groupClause = new_groupby;
}
}
* Note: we need no comparable processing of the distinctClause because
* the parser already enforced that that matches ORDER BY.
*
+ * Note: we return a fresh List, but its elements are the same
+ * SortGroupClauses appearing in parse->groupClause. This is important
+ * because later processing may modify the processed_groupClause list.
+ *
* For grouping sets, the order of items is instead forced to agree with that
* of the grouping set (and items not in the grouping set are skipped). The
* work of sorting the order of grouping set elements to match the ORDER BY if
/* If no ORDER BY, nothing useful to do here */
if (parse->sortClause == NIL)
- return parse->groupClause;
+ return list_copy(parse->groupClause);
/*
* Scan the ORDER BY clause and construct a list of matching GROUP BY
/* If no match at all, no point in reordering GROUP BY */
if (new_groupclause == NIL)
- return parse->groupClause;
+ return list_copy(parse->groupClause);
/*
* Add any remaining GROUP BY items to the new list, but only if we were
if (list_member_ptr(new_groupclause, gc))
continue; /* it matched an ORDER BY item */
- if (partial_match)
- return parse->groupClause; /* give up, no common sort possible */
- if (!OidIsValid(gc->sortop))
- return parse->groupClause; /* give up, GROUP BY can't be sorted */
+ if (partial_match) /* give up, no common sort possible */
+ return list_copy(parse->groupClause);
+ if (!OidIsValid(gc->sortop)) /* give up, GROUP BY can't be sorted */
+ return list_copy(parse->groupClause);
new_groupclause = lappend(new_groupclause, gc);
}
}
/*
- * make_pathkeys_for_groupagg
- * Determine the pathkeys for the GROUP BY clause and/or any ordered
- * aggregates. We expect at least one of these here.
+ * adjust_group_pathkeys_for_groupagg
+ * Add pathkeys to root->group_pathkeys to reflect the best set of
+ * pre-ordered input for ordered aggregates.
*
- * Building the pathkeys for the GROUP BY is simple. Most of the complexity
- * involved here comes from calculating the best pathkeys for ordered
- * aggregates. We define "best" as the pathkeys that suit the most number of
+ * We define "best" as the pathkeys that suit the largest number of
* aggregate functions. We find these by looking at the first ORDER BY /
* DISTINCT aggregate and take the pathkeys for that before searching for
* other aggregates that require the same or a more strict variation of the
* same pathkeys. We then repeat that process for any remaining aggregates
* with different pathkeys and if we find another set of pathkeys that suits a
- * larger number of aggregates then we return those pathkeys instead.
- *
- * *number_groupby_pathkeys gets set to the number of elements in the returned
- * list that belong to the GROUP BY clause. Any elements above this number
- * must belong to ORDER BY / DISTINCT aggregates.
+ * larger number of aggregates then we select those pathkeys instead.
*
* When the best pathkeys are found we also mark each Aggref that can use
* those pathkeys as aggpresorted = true.
* query contains, we always force Aggrefs with volatile functions to perform
* their own sorts.
*/
-static List *
-make_pathkeys_for_groupagg(PlannerInfo *root, List *groupClause, List *tlist,
- int *number_groupby_pathkeys)
+static void
+adjust_group_pathkeys_for_groupagg(PlannerInfo *root)
{
- List *grouppathkeys = NIL;
+ List *grouppathkeys = root->group_pathkeys;
List *bestpathkeys;
Bitmapset *bestaggs;
Bitmapset *unprocessed_aggs;
ListCell *lc;
int i;
- Assert(groupClause != NIL || root->numOrderedAggs > 0);
-
- if (groupClause != NIL)
- {
- /* no pathkeys possible if there's an unsortable GROUP BY */
- if (!grouping_is_sortable(groupClause))
- {
- *number_groupby_pathkeys = 0;
- return NIL;
- }
+ /* Shouldn't be here if there are grouping sets */
+ Assert(root->parse->groupingSets == NIL);
+ /* Shouldn't be here unless there are some ordered aggregates */
+ Assert(root->numOrderedAggs > 0);
- grouppathkeys = make_pathkeys_for_sortclauses(root, groupClause,
- tlist);
- *number_groupby_pathkeys = list_length(grouppathkeys);
- }
- else
- *number_groupby_pathkeys = 0;
-
- /*
- * We can't add pathkeys for ordered aggregates if there are any grouping
- * sets. All handling specific to ordered aggregates must be done by the
- * executor in that case.
- */
- if (root->numOrderedAggs == 0 || root->parse->groupingSets != NIL ||
- !enable_presorted_aggregate)
- return grouppathkeys;
+ /* Do nothing if disabled */
+ if (!enable_presorted_aggregate)
+ return;
/*
* Make a first pass over all AggInfos to collect a Bitmapset containing
}
}
+ /*
+ * If we found any ordered aggregates, update root->group_pathkeys to add
+ * the best set of aggregate pathkeys. Note that bestpathkeys includes
+ * the original GROUP BY pathkeys already.
+ */
+ if (bestpathkeys != NIL)
+ root->group_pathkeys = bestpathkeys;
+
/*
* Now that we've found the best set of aggregates we can set the
* presorted flag to indicate to the executor that it needn't bother
aggref->aggpresorted = true;
}
}
-
- /*
- * bestpathkeys includes the GROUP BY pathkeys, so if we found any ordered
- * aggregates, then return bestpathkeys, otherwise return the
- * grouppathkeys.
- */
- if (bestpathkeys != NIL)
- return bestpathkeys;
-
- return grouppathkeys;
}
/*
* Calculate pathkeys that represent grouping/ordering and/or ordered
* aggregate requirements.
*/
- if (qp_extra->groupClause != NIL || root->numOrderedAggs > 0)
- root->group_pathkeys = make_pathkeys_for_groupagg(root,
- qp_extra->groupClause,
- tlist,
- &root->num_groupby_pathkeys);
+ if (qp_extra->gset_data)
+ {
+ /*
+ * With grouping sets, just use the first RollupData's groupClause. We
+ * don't make any effort to optimize grouping clauses when there are
+ * grouping sets, nor can we combine aggregate ordering keys with
+ * grouping.
+ */
+ List *rollups = qp_extra->gset_data->rollups;
+ List *groupClause = (rollups ? linitial_node(RollupData, rollups)->groupClause : NIL);
+
+ if (grouping_is_sortable(groupClause))
+ {
+ root->group_pathkeys = make_pathkeys_for_sortclauses(root,
+ groupClause,
+ tlist);
+ root->num_groupby_pathkeys = list_length(root->group_pathkeys);
+ }
+ else
+ {
+ root->group_pathkeys = NIL;
+ root->num_groupby_pathkeys = 0;
+ }
+ }
+ else if (parse->groupClause || root->numOrderedAggs > 0)
+ {
+ /*
+ * With a plain GROUP BY list, we can remove any grouping items that
+ * are proven redundant by EquivalenceClass processing. For example,
+ * we can remove y given "WHERE x = y GROUP BY x, y". These aren't
+ * especially common cases, but they're nearly free to detect. Note
+ * that we remove redundant items from processed_groupClause but not
+ * the original parse->groupClause.
+ */
+ bool sortable;
+
+ root->group_pathkeys =
+ make_pathkeys_for_sortclauses_extended(root,
+ &root->processed_groupClause,
+ tlist,
+ true,
+ &sortable);
+ if (!sortable)
+ {
+ /* Can't sort; no point in considering aggregate ordering either */
+ root->group_pathkeys = NIL;
+ root->num_groupby_pathkeys = 0;
+ }
+ else
+ {
+ root->num_groupby_pathkeys = list_length(root->group_pathkeys);
+ /* If we have ordered aggs, consider adding onto group_pathkeys */
+ if (root->numOrderedAggs > 0)
+ adjust_group_pathkeys_for_groupagg(root);
+ }
+ }
else
{
root->group_pathkeys = NIL;
else
root->window_pathkeys = NIL;
- if (parse->distinctClause &&
- grouping_is_sortable(parse->distinctClause))
+ /*
+ * As with GROUP BY, we can discard any DISTINCT items that are proven
+ * redundant by EquivalenceClass processing. The non-redundant list is
+ * kept in root->processed_distinctClause, leaving the original
+ * parse->distinctClause alone.
+ */
+ if (parse->distinctClause)
+ {
+ bool sortable;
+
+ /* Make a copy since pathkey processing can modify the list */
+ root->processed_distinctClause = list_copy(parse->distinctClause);
root->distinct_pathkeys =
- make_pathkeys_for_sortclauses(root,
- parse->distinctClause,
- tlist);
+ make_pathkeys_for_sortclauses_extended(root,
+ &root->processed_distinctClause,
+ tlist,
+ true,
+ &sortable);
+ if (!sortable)
+ root->distinct_pathkeys = NIL;
+ }
else
root->distinct_pathkeys = NIL;
}
else
{
- /* Plain GROUP BY */
- groupExprs = get_sortgrouplist_exprs(parse->groupClause,
+ /* Plain GROUP BY -- estimate based on optimized groupClause */
+ groupExprs = get_sortgrouplist_exprs(root->processed_groupClause,
target_list);
dNumGroups = estimate_num_groups(root, groupExprs, path_rows,
/*
* Determine whether it's possible to perform sort-based
- * implementations of grouping. (Note that if groupClause is empty,
- * grouping_is_sortable() is trivially true, and all the
+ * implementations of grouping. (Note that if processed_groupClause
+ * is empty, grouping_is_sortable() is trivially true, and all the
* pathkeys_contained_in() tests will succeed too, so that we'll
* consider every surviving input path.)
*
* must consider any sorted-input plan.
*/
if ((gd && gd->rollups != NIL)
- || grouping_is_sortable(parse->groupClause))
+ || grouping_is_sortable(root->processed_groupClause))
flags |= GROUPING_CAN_USE_SORT;
/*
*/
if ((parse->groupClause != NIL &&
root->numOrderedAggs == 0 &&
- (gd ? gd->any_hashable : grouping_is_hashable(parse->groupClause))))
+ (gd ? gd->any_hashable : grouping_is_hashable(root->processed_groupClause))))
flags |= GROUPING_CAN_USE_HASH;
/*
* partial partitionwise aggregation. But if partial aggregation is
* not supported in general then we can't use it for partitionwise
* aggregation either.
+ *
+ * Check parse->groupClause not processed_groupClause, because it's
+ * okay if some of the partitioning columns were proved redundant.
*/
if (extra->patype == PARTITIONWISE_AGGREGATE_FULL &&
group_by_has_partkey(input_rel, extra->targetList,
cheapest_partial_path = linitial(input_rel->partial_pathlist);
- distinctExprs = get_sortgrouplist_exprs(parse->distinctClause,
+ distinctExprs = get_sortgrouplist_exprs(root->processed_distinctClause,
parse->targetList);
/* estimate how many distinct rows we'll get from each worker */
* Try sorting the cheapest path and incrementally sorting any paths with
* presorted keys and put a unique paths atop of those.
*/
- if (grouping_is_sortable(parse->distinctClause))
+ if (grouping_is_sortable(root->processed_distinctClause))
{
foreach(lc, input_rel->partial_pathlist)
{
* path here, we treat enable_hashagg as a hard off-switch rather than the
* slightly softer variant in create_final_distinct_paths.
*/
- if (enable_hashagg && grouping_is_hashable(parse->distinctClause))
+ if (enable_hashagg && grouping_is_hashable(root->processed_distinctClause))
{
add_partial_path(partial_distinct_rel, (Path *)
create_agg_path(root,
cheapest_partial_path->pathtarget,
AGG_HASHED,
AGGSPLIT_SIMPLE,
- parse->distinctClause,
+ root->processed_distinctClause,
NIL,
NULL,
numDistinctRows));
*/
List *distinctExprs;
- distinctExprs = get_sortgrouplist_exprs(parse->distinctClause,
+ distinctExprs = get_sortgrouplist_exprs(root->processed_distinctClause,
parse->targetList);
numDistinctRows = estimate_num_groups(root, distinctExprs,
cheapest_input_path->rows,
/*
* Consider sort-based implementations of DISTINCT, if possible.
*/
- if (grouping_is_sortable(parse->distinctClause))
+ if (grouping_is_sortable(root->processed_distinctClause))
{
/*
* Firstly, if we have any adequately-presorted paths, just stick a
else
allow_hash = true; /* default */
- if (allow_hash && grouping_is_hashable(parse->distinctClause))
+ if (allow_hash && grouping_is_hashable(root->processed_distinctClause))
{
/* Generate hashed aggregate path --- no sort needed */
add_path(distinct_rel, (Path *)
cheapest_input_path->pathtarget,
AGG_HASHED,
AGGSPLIT_SIMPLE,
- parse->distinctClause,
+ root->processed_distinctClause,
NIL,
NULL,
numDistinctRows));
Expr *expr = (Expr *) lfirst(lc);
Index sgref = get_pathtarget_sortgroupref(final_target, i);
- if (sgref && parse->groupClause &&
- get_sortgroupref_clause_noerr(sgref, parse->groupClause) != NULL)
+ if (sgref && root->processed_groupClause &&
+ get_sortgroupref_clause_noerr(sgref,
+ root->processed_groupClause) != NULL)
{
/*
* It's a grouping column, so add it to the input target as-is.
PathTarget *grouping_target,
Node *havingQual)
{
- Query *parse = root->parse;
PathTarget *partial_target;
List *non_group_cols;
List *non_group_exprs;
Expr *expr = (Expr *) lfirst(lc);
Index sgref = get_pathtarget_sortgroupref(grouping_target, i);
- if (sgref && parse->groupClause &&
- get_sortgroupref_clause_noerr(sgref, parse->groupClause) != NULL)
+ if (sgref && root->processed_groupClause &&
+ get_sortgroupref_clause_noerr(sgref,
+ root->processed_groupClause) != NULL)
{
/*
* It's a grouping column, so add it to the partial_target as-is.
PathTarget *final_target,
List *activeWindows)
{
- Query *parse = root->parse;
PathTarget *input_target;
Bitmapset *sgrefs;
List *flattenable_cols;
int i;
ListCell *lc;
- Assert(parse->hasWindowFuncs);
+ Assert(root->parse->hasWindowFuncs);
/*
* Collect the sortgroupref numbers of window PARTITION/ORDER BY clauses
}
/* Add in sortgroupref numbers of GROUP BY clauses, too */
- foreach(lc, parse->groupClause)
+ foreach(lc, root->processed_groupClause)
{
SortGroupClause *grpcl = lfirst_node(SortGroupClause, lc);
grouped_rel->reltarget,
parse->groupClause ? AGG_SORTED : AGG_PLAIN,
AGGSPLIT_SIMPLE,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
agg_costs,
dNumGroups));
create_group_path(root,
grouped_rel,
path,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
dNumGroups));
}
grouped_rel->reltarget,
parse->groupClause ? AGG_SORTED : AGG_PLAIN,
AGGSPLIT_FINAL_DESERIAL,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
agg_final_costs,
dNumGroups));
create_group_path(root,
grouped_rel,
path,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
dNumGroups));
grouped_rel->reltarget,
AGG_HASHED,
AGGSPLIT_SIMPLE,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
agg_costs,
dNumGroups));
grouped_rel->reltarget,
AGG_HASHED,
AGGSPLIT_FINAL_DESERIAL,
- parse->groupClause,
+ root->processed_groupClause,
havingQual,
agg_final_costs,
dNumGroups));
partially_grouped_rel->reltarget,
parse->groupClause ? AGG_SORTED : AGG_PLAIN,
AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
agg_partial_costs,
dNumPartialGroups));
create_group_path(root,
partially_grouped_rel,
path,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
dNumPartialGroups));
}
partially_grouped_rel->reltarget,
parse->groupClause ? AGG_SORTED : AGG_PLAIN,
AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
agg_partial_costs,
dNumPartialPartialGroups));
create_group_path(root,
partially_grouped_rel,
path,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
dNumPartialPartialGroups));
}
partially_grouped_rel->reltarget,
AGG_HASHED,
AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
agg_partial_costs,
dNumPartialGroups));
partially_grouped_rel->reltarget,
AGG_HASHED,
AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
+ root->processed_groupClause,
NIL,
agg_partial_costs,
dNumPartialPartialGroups));
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