bool *have_postponed_srfs);
static void adjust_paths_for_srfs(PlannerInfo *root, RelOptInfo *rel,
List *targets, List *targets_contain_srfs);
+static void add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel, PathTarget *target,
+ PathTarget *partial_grouping_target,
+ const AggClauseCosts *agg_costs,
+ const AggClauseCosts *agg_final_costs,
+ grouping_sets_data *gd, bool can_sort, bool can_hash,
+ double dNumGroups, List *havingQual);
+static void add_partial_paths_to_grouping_rel(PlannerInfo *root,
+ RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel,
+ PathTarget *target,
+ PathTarget *partial_grouping_target,
+ AggClauseCosts *agg_partial_costs,
+ AggClauseCosts *agg_final_costs,
+ grouping_sets_data *gd,
+ bool can_sort,
+ bool can_hash,
+ List *havingQual);
+static bool can_parallel_agg(PlannerInfo *root, RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel, const AggClauseCosts *agg_costs);
/*****************************************************************************
PathTarget *partial_grouping_target = NULL;
AggClauseCosts agg_partial_costs; /* parallel only */
AggClauseCosts agg_final_costs; /* parallel only */
- Size hashaggtablesize;
double dNumGroups;
- double dNumPartialGroups = 0;
bool can_hash;
bool can_sort;
bool try_parallel_aggregation;
- ListCell *lc;
-
/* For now, do all work in the (GROUP_AGG, NULL) upperrel */
grouped_rel = fetch_upper_rel(root, UPPERREL_GROUP_AGG, NULL);
(gd ? gd->any_hashable : grouping_is_hashable(parse->groupClause)));
/*
- * If grouped_rel->consider_parallel is true, then paths that we generate
- * for this grouping relation could be run inside of a worker, but that
- * doesn't mean we can actually use the PartialAggregate/FinalizeAggregate
- * execution strategy. Figure that out.
+ * Figure out whether a PartialAggregate/Finalize Aggregate execution
+ * strategy is viable.
*/
- if (!grouped_rel->consider_parallel)
- {
- /* Not even parallel-safe. */
- try_parallel_aggregation = false;
- }
- else if (input_rel->partial_pathlist == NIL)
- {
- /* Nothing to use as input for partial aggregate. */
- try_parallel_aggregation = false;
- }
- else if (!parse->hasAggs && parse->groupClause == NIL)
- {
- /*
- * We don't know how to do parallel aggregation unless we have either
- * some aggregates or a grouping clause.
- */
- try_parallel_aggregation = false;
- }
- else if (parse->groupingSets)
- {
- /* We don't know how to do grouping sets in parallel. */
- try_parallel_aggregation = false;
- }
- else if (agg_costs->hasNonPartial || agg_costs->hasNonSerial)
- {
- /* Insufficient support for partial mode. */
- try_parallel_aggregation = false;
- }
- else
- {
- /* Everything looks good. */
- try_parallel_aggregation = true;
- }
+ try_parallel_aggregation = can_parallel_agg(root, input_rel, grouped_rel,
+ agg_costs);
/*
* Before generating paths for grouped_rel, we first generate any possible
*/
if (try_parallel_aggregation)
{
- Path *cheapest_partial_path = linitial(input_rel->partial_pathlist);
-
/*
* Build target list for partial aggregate paths. These paths cannot
* just emit the same tlist as regular aggregate paths, because (1) we
*/
partial_grouping_target = make_partial_grouping_target(root, target);
- /* Estimate number of partial groups. */
- dNumPartialGroups = get_number_of_groups(root,
- cheapest_partial_path->rows,
- gd);
-
/*
* Collect statistics about aggregates for estimating costs of
* performing aggregation in parallel.
&agg_final_costs);
}
- if (can_sort)
- {
- /* This was checked before setting try_parallel_aggregation */
- Assert(parse->hasAggs || parse->groupClause);
+ add_partial_paths_to_grouping_rel(root, input_rel, grouped_rel, target,
+ partial_grouping_target,
+ &agg_partial_costs, &agg_final_costs,
+ gd, can_sort, can_hash,
+ (List *) parse->havingQual);
+ }
- /*
- * Use any available suitably-sorted path as input, and also
- * consider sorting the cheapest partial path.
- */
- foreach(lc, input_rel->partial_pathlist)
- {
- Path *path = (Path *) lfirst(lc);
- bool is_sorted;
+ /* Build final grouping paths */
+ add_paths_to_grouping_rel(root, input_rel, grouped_rel, target,
+ partial_grouping_target, agg_costs,
+ &agg_final_costs, gd, can_sort, can_hash,
+ dNumGroups, (List *) parse->havingQual);
- is_sorted = pathkeys_contained_in(root->group_pathkeys,
- path->pathkeys);
- if (path == cheapest_partial_path || is_sorted)
- {
- /* Sort the cheapest partial path, if it isn't already */
- if (!is_sorted)
- path = (Path *) create_sort_path(root,
- grouped_rel,
- path,
- root->group_pathkeys,
- -1.0);
+ /* Give a helpful error if we failed to find any implementation */
+ if (grouped_rel->pathlist == NIL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("could not implement GROUP BY"),
+ errdetail("Some of the datatypes only support hashing, while others only support sorting.")));
- if (parse->hasAggs)
- add_partial_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- path,
- partial_grouping_target,
- parse->groupClause ? AGG_SORTED : AGG_PLAIN,
- AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
- NIL,
- &agg_partial_costs,
- dNumPartialGroups));
- else
- add_partial_path(grouped_rel, (Path *)
- create_group_path(root,
- grouped_rel,
- path,
- partial_grouping_target,
- parse->groupClause,
- NIL,
- dNumPartialGroups));
- }
- }
- }
+ /*
+ * If there is an FDW that's responsible for all baserels of the query,
+ * let it consider adding ForeignPaths.
+ */
+ if (grouped_rel->fdwroutine &&
+ grouped_rel->fdwroutine->GetForeignUpperPaths)
+ grouped_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_GROUP_AGG,
+ input_rel, grouped_rel);
- if (can_hash)
- {
- /* Checked above */
- Assert(parse->hasAggs || parse->groupClause);
+ /* Let extensions possibly add some more paths */
+ if (create_upper_paths_hook)
+ (*create_upper_paths_hook) (root, UPPERREL_GROUP_AGG,
+ input_rel, grouped_rel);
+
+ /* Now choose the best path(s) */
+ set_cheapest(grouped_rel);
- hashaggtablesize =
- estimate_hashagg_tablesize(cheapest_partial_path,
- &agg_partial_costs,
- dNumPartialGroups);
+ /*
+ * We've been using the partial pathlist for the grouped relation to hold
+ * partially aggregated paths, but that's actually a little bit bogus
+ * because it's unsafe for later planning stages -- like ordered_rel ---
+ * to get the idea that they can use these partial paths as if they didn't
+ * need a FinalizeAggregate step. Zap the partial pathlist at this stage
+ * so we don't get confused.
+ */
+ grouped_rel->partial_pathlist = NIL;
- /*
- * Tentatively produce a partial HashAgg Path, depending on if it
- * looks as if the hash table will fit in work_mem.
- */
- if (hashaggtablesize < work_mem * 1024L)
- {
- add_partial_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- cheapest_partial_path,
- partial_grouping_target,
- AGG_HASHED,
- AGGSPLIT_INITIAL_SERIAL,
- parse->groupClause,
- NIL,
- &agg_partial_costs,
- dNumPartialGroups));
- }
- }
- }
+ return grouped_rel;
+}
- /* Build final grouping paths */
- if (can_sort)
+
+/*
+ * For a given input path, consider the possible ways of doing grouping sets on
+ * it, by combinations of hashing and sorting. This can be called multiple
+ * times, so it's important that it not scribble on input. No result is
+ * returned, but any generated paths are added to grouped_rel.
+ */
+static void
+consider_groupingsets_paths(PlannerInfo *root,
+ RelOptInfo *grouped_rel,
+ Path *path,
+ bool is_sorted,
+ bool can_hash,
+ PathTarget *target,
+ grouping_sets_data *gd,
+ const AggClauseCosts *agg_costs,
+ double dNumGroups)
+{
+ Query *parse = root->parse;
+
+ /*
+ * If we're not being offered sorted input, then only consider plans that
+ * can be done entirely by hashing.
+ *
+ * We can hash everything if it looks like it'll fit in work_mem. But if
+ * the input is actually sorted despite not being advertised as such, we
+ * prefer to make use of that in order to use less memory.
+ *
+ * If none of the grouping sets are sortable, then ignore the work_mem
+ * limit and generate a path anyway, since otherwise we'll just fail.
+ */
+ if (!is_sorted)
{
- /*
- * Use any available suitably-sorted path as input, and also consider
- * sorting the cheapest-total path.
- */
- foreach(lc, input_rel->pathlist)
- {
- Path *path = (Path *) lfirst(lc);
- bool is_sorted;
+ List *new_rollups = NIL;
+ RollupData *unhashed_rollup = NULL;
+ List *sets_data;
+ List *empty_sets_data = NIL;
+ List *empty_sets = NIL;
+ ListCell *lc;
+ ListCell *l_start = list_head(gd->rollups);
+ AggStrategy strat = AGG_HASHED;
+ Size hashsize;
+ double exclude_groups = 0.0;
- is_sorted = pathkeys_contained_in(root->group_pathkeys,
- path->pathkeys);
- if (path == cheapest_path || is_sorted)
- {
- /* Sort the cheapest-total path if it isn't already sorted */
- if (!is_sorted)
- path = (Path *) create_sort_path(root,
- grouped_rel,
- path,
- root->group_pathkeys,
- -1.0);
+ Assert(can_hash);
- /* Now decide what to stick atop it */
- if (parse->groupingSets)
- {
- consider_groupingsets_paths(root, grouped_rel,
- path, true, can_hash, target,
- gd, agg_costs, dNumGroups);
- }
- else if (parse->hasAggs)
- {
- /*
- * We have aggregation, possibly with plain GROUP BY. Make
- * an AggPath.
- */
- add_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- path,
- target,
- parse->groupClause ? AGG_SORTED : AGG_PLAIN,
- AGGSPLIT_SIMPLE,
- parse->groupClause,
- (List *) parse->havingQual,
- agg_costs,
- dNumGroups));
- }
- else if (parse->groupClause)
- {
- /*
- * We have GROUP BY without aggregation or grouping sets.
- * Make a GroupPath.
- */
- add_path(grouped_rel, (Path *)
- create_group_path(root,
- grouped_rel,
- path,
- target,
- parse->groupClause,
- (List *) parse->havingQual,
- dNumGroups));
- }
- else
- {
- /* Other cases should have been handled above */
- Assert(false);
- }
- }
+ if (pathkeys_contained_in(root->group_pathkeys, path->pathkeys))
+ {
+ unhashed_rollup = lfirst_node(RollupData, l_start);
+ exclude_groups = unhashed_rollup->numGroups;
+ l_start = lnext(l_start);
}
+ hashsize = estimate_hashagg_tablesize(path,
+ agg_costs,
+ dNumGroups - exclude_groups);
+
/*
- * Now generate a complete GroupAgg Path atop of the cheapest partial
- * path. We can do this using either Gather or Gather Merge.
+ * gd->rollups is empty if we have only unsortable columns to work
+ * with. Override work_mem in that case; otherwise, we'll rely on the
+ * sorted-input case to generate usable mixed paths.
*/
- if (grouped_rel->partial_pathlist)
- {
- Path *path = (Path *) linitial(grouped_rel->partial_pathlist);
- double total_groups = path->rows * path->parallel_workers;
+ if (hashsize > work_mem * 1024L && gd->rollups)
+ return; /* nope, won't fit */
- path = (Path *) create_gather_path(root,
- grouped_rel,
- path,
- partial_grouping_target,
- NULL,
- &total_groups);
+ /*
+ * We need to burst the existing rollups list into individual grouping
+ * sets and recompute a groupClause for each set.
+ */
+ sets_data = list_copy(gd->unsortable_sets);
+
+ for_each_cell(lc, l_start)
+ {
+ RollupData *rollup = lfirst_node(RollupData, lc);
/*
- * Since Gather's output is always unsorted, we'll need to sort,
- * unless there's no GROUP BY clause or a degenerate (constant)
- * one, in which case there will only be a single group.
- */
- if (root->group_pathkeys)
- path = (Path *) create_sort_path(root,
- grouped_rel,
- path,
- root->group_pathkeys,
- -1.0);
-
- if (parse->hasAggs)
- add_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- path,
- target,
- parse->groupClause ? AGG_SORTED : AGG_PLAIN,
- AGGSPLIT_FINAL_DESERIAL,
- parse->groupClause,
- (List *) parse->havingQual,
- &agg_final_costs,
- dNumGroups));
- else
- add_path(grouped_rel, (Path *)
- create_group_path(root,
- grouped_rel,
- path,
- target,
- parse->groupClause,
- (List *) parse->havingQual,
- dNumGroups));
-
- /*
- * The point of using Gather Merge rather than Gather is that it
- * can preserve the ordering of the input path, so there's no
- * reason to try it unless (1) it's possible to produce more than
- * one output row and (2) we want the output path to be ordered.
- */
- if (parse->groupClause != NIL && root->group_pathkeys != NIL)
- {
- foreach(lc, grouped_rel->partial_pathlist)
- {
- Path *subpath = (Path *) lfirst(lc);
- Path *gmpath;
- double total_groups;
-
- /*
- * It's useful to consider paths that are already properly
- * ordered for Gather Merge, because those don't need a
- * sort. It's also useful to consider the cheapest path,
- * because sorting it in parallel and then doing Gather
- * Merge may be better than doing an unordered Gather
- * followed by a sort. But there's no point in
- * considering non-cheapest paths that aren't already
- * sorted correctly.
- */
- if (path != subpath &&
- !pathkeys_contained_in(root->group_pathkeys,
- subpath->pathkeys))
- continue;
-
- total_groups = subpath->rows * subpath->parallel_workers;
-
- gmpath = (Path *)
- create_gather_merge_path(root,
- grouped_rel,
- subpath,
- partial_grouping_target,
- root->group_pathkeys,
- NULL,
- &total_groups);
-
- if (parse->hasAggs)
- add_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- gmpath,
- target,
- parse->groupClause ? AGG_SORTED : AGG_PLAIN,
- AGGSPLIT_FINAL_DESERIAL,
- parse->groupClause,
- (List *) parse->havingQual,
- &agg_final_costs,
- dNumGroups));
- else
- add_path(grouped_rel, (Path *)
- create_group_path(root,
- grouped_rel,
- gmpath,
- target,
- parse->groupClause,
- (List *) parse->havingQual,
- dNumGroups));
- }
- }
- }
- }
-
- if (can_hash)
- {
- if (parse->groupingSets)
- {
- /*
- * Try for a hash-only groupingsets path over unsorted input.
- */
- consider_groupingsets_paths(root, grouped_rel,
- cheapest_path, false, true, target,
- gd, agg_costs, dNumGroups);
- }
- else
- {
- hashaggtablesize = estimate_hashagg_tablesize(cheapest_path,
- agg_costs,
- dNumGroups);
-
- /*
- * Provided that the estimated size of the hashtable does not
- * exceed work_mem, we'll generate a HashAgg Path, although if we
- * were unable to sort above, then we'd better generate a Path, so
- * that we at least have one.
- */
- if (hashaggtablesize < work_mem * 1024L ||
- grouped_rel->pathlist == NIL)
- {
- /*
- * We just need an Agg over the cheapest-total input path,
- * since input order won't matter.
- */
- add_path(grouped_rel, (Path *)
- create_agg_path(root, grouped_rel,
- cheapest_path,
- target,
- AGG_HASHED,
- AGGSPLIT_SIMPLE,
- parse->groupClause,
- (List *) parse->havingQual,
- agg_costs,
- dNumGroups));
- }
- }
-
- /*
- * Generate a HashAgg Path atop of the cheapest partial path. Once
- * again, we'll only do this if it looks as though the hash table
- * won't exceed work_mem.
- */
- if (grouped_rel->partial_pathlist)
- {
- Path *path = (Path *) linitial(grouped_rel->partial_pathlist);
-
- hashaggtablesize = estimate_hashagg_tablesize(path,
- &agg_final_costs,
- dNumGroups);
-
- if (hashaggtablesize < work_mem * 1024L)
- {
- double total_groups = path->rows * path->parallel_workers;
-
- path = (Path *) create_gather_path(root,
- grouped_rel,
- path,
- partial_grouping_target,
- NULL,
- &total_groups);
-
- add_path(grouped_rel, (Path *)
- create_agg_path(root,
- grouped_rel,
- path,
- target,
- AGG_HASHED,
- AGGSPLIT_FINAL_DESERIAL,
- parse->groupClause,
- (List *) parse->havingQual,
- &agg_final_costs,
- dNumGroups));
- }
- }
- }
-
- /* Give a helpful error if we failed to find any implementation */
- if (grouped_rel->pathlist == NIL)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("could not implement GROUP BY"),
- errdetail("Some of the datatypes only support hashing, while others only support sorting.")));
-
- /*
- * If there is an FDW that's responsible for all baserels of the query,
- * let it consider adding ForeignPaths.
- */
- if (grouped_rel->fdwroutine &&
- grouped_rel->fdwroutine->GetForeignUpperPaths)
- grouped_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_GROUP_AGG,
- input_rel, grouped_rel);
-
- /* Let extensions possibly add some more paths */
- if (create_upper_paths_hook)
- (*create_upper_paths_hook) (root, UPPERREL_GROUP_AGG,
- input_rel, grouped_rel);
-
- /* Now choose the best path(s) */
- set_cheapest(grouped_rel);
-
- /*
- * We've been using the partial pathlist for the grouped relation to hold
- * partially aggregated paths, but that's actually a little bit bogus
- * because it's unsafe for later planning stages -- like ordered_rel ---
- * to get the idea that they can use these partial paths as if they didn't
- * need a FinalizeAggregate step. Zap the partial pathlist at this stage
- * so we don't get confused.
- */
- grouped_rel->partial_pathlist = NIL;
-
- return grouped_rel;
-}
-
-
-/*
- * For a given input path, consider the possible ways of doing grouping sets on
- * it, by combinations of hashing and sorting. This can be called multiple
- * times, so it's important that it not scribble on input. No result is
- * returned, but any generated paths are added to grouped_rel.
- */
-static void
-consider_groupingsets_paths(PlannerInfo *root,
- RelOptInfo *grouped_rel,
- Path *path,
- bool is_sorted,
- bool can_hash,
- PathTarget *target,
- grouping_sets_data *gd,
- const AggClauseCosts *agg_costs,
- double dNumGroups)
-{
- Query *parse = root->parse;
-
- /*
- * If we're not being offered sorted input, then only consider plans that
- * can be done entirely by hashing.
- *
- * We can hash everything if it looks like it'll fit in work_mem. But if
- * the input is actually sorted despite not being advertised as such, we
- * prefer to make use of that in order to use less memory.
- *
- * If none of the grouping sets are sortable, then ignore the work_mem
- * limit and generate a path anyway, since otherwise we'll just fail.
- */
- if (!is_sorted)
- {
- List *new_rollups = NIL;
- RollupData *unhashed_rollup = NULL;
- List *sets_data;
- List *empty_sets_data = NIL;
- List *empty_sets = NIL;
- ListCell *lc;
- ListCell *l_start = list_head(gd->rollups);
- AggStrategy strat = AGG_HASHED;
- Size hashsize;
- double exclude_groups = 0.0;
-
- Assert(can_hash);
-
- if (pathkeys_contained_in(root->group_pathkeys, path->pathkeys))
- {
- unhashed_rollup = lfirst_node(RollupData, l_start);
- exclude_groups = unhashed_rollup->numGroups;
- l_start = lnext(l_start);
- }
-
- hashsize = estimate_hashagg_tablesize(path,
- agg_costs,
- dNumGroups - exclude_groups);
-
- /*
- * gd->rollups is empty if we have only unsortable columns to work
- * with. Override work_mem in that case; otherwise, we'll rely on the
- * sorted-input case to generate usable mixed paths.
- */
- if (hashsize > work_mem * 1024L && gd->rollups)
- return; /* nope, won't fit */
-
- /*
- * We need to burst the existing rollups list into individual grouping
- * sets and recompute a groupClause for each set.
- */
- sets_data = list_copy(gd->unsortable_sets);
-
- for_each_cell(lc, l_start)
- {
- RollupData *rollup = lfirst_node(RollupData, lc);
-
- /*
- * If we find an unhashable rollup that's not been skipped by the
- * "actually sorted" check above, we can't cope; we'd need sorted
- * input (with a different sort order) but we can't get that here.
- * So bail out; we'll get a valid path from the is_sorted case
- * instead.
- *
- * The mere presence of empty grouping sets doesn't make a rollup
- * unhashable (see preprocess_grouping_sets), we handle those
- * specially below.
+ * If we find an unhashable rollup that's not been skipped by the
+ * "actually sorted" check above, we can't cope; we'd need sorted
+ * input (with a different sort order) but we can't get that here.
+ * So bail out; we'll get a valid path from the is_sorted case
+ * instead.
+ *
+ * The mere presence of empty grouping sets doesn't make a rollup
+ * unhashable (see preprocess_grouping_sets), we handle those
+ * specially below.
*/
if (!rollup->hashable)
return;
rel->cheapest_total_path = newpath;
}
- /* Likewise for partial paths, if any */
- foreach(lc, rel->partial_pathlist)
+ /* Likewise for partial paths, if any */
+ foreach(lc, rel->partial_pathlist)
+ {
+ Path *subpath = (Path *) lfirst(lc);
+ Path *newpath = subpath;
+ ListCell *lc1,
+ *lc2;
+
+ Assert(subpath->param_info == NULL);
+ forboth(lc1, targets, lc2, targets_contain_srfs)
+ {
+ PathTarget *thistarget = lfirst_node(PathTarget, lc1);
+ bool contains_srfs = (bool) lfirst_int(lc2);
+
+ /* If this level doesn't contain SRFs, do regular projection */
+ if (contains_srfs)
+ newpath = (Path *) create_set_projection_path(root,
+ rel,
+ newpath,
+ thistarget);
+ else
+ {
+ /* avoid apply_projection_to_path, in case of multiple refs */
+ newpath = (Path *) create_projection_path(root,
+ rel,
+ newpath,
+ thistarget);
+ }
+ }
+ lfirst(lc) = newpath;
+ }
+}
+
+/*
+ * expression_planner
+ * Perform planner's transformations on a standalone expression.
+ *
+ * Various utility commands need to evaluate expressions that are not part
+ * of a plannable query. They can do so using the executor's regular
+ * expression-execution machinery, but first the expression has to be fed
+ * through here to transform it from parser output to something executable.
+ *
+ * Currently, we disallow sublinks in standalone expressions, so there's no
+ * real "planning" involved here. (That might not always be true though.)
+ * What we must do is run eval_const_expressions to ensure that any function
+ * calls are converted to positional notation and function default arguments
+ * get inserted. The fact that constant subexpressions get simplified is a
+ * side-effect that is useful when the expression will get evaluated more than
+ * once. Also, we must fix operator function IDs.
+ *
+ * Note: this must not make any damaging changes to the passed-in expression
+ * tree. (It would actually be okay to apply fix_opfuncids to it, but since
+ * we first do an expression_tree_mutator-based walk, what is returned will
+ * be a new node tree.)
+ */
+Expr *
+expression_planner(Expr *expr)
+{
+ Node *result;
+
+ /*
+ * Convert named-argument function calls, insert default arguments and
+ * simplify constant subexprs
+ */
+ result = eval_const_expressions(NULL, (Node *) expr);
+
+ /* Fill in opfuncid values if missing */
+ fix_opfuncids(result);
+
+ return (Expr *) result;
+}
+
+
+/*
+ * plan_cluster_use_sort
+ * Use the planner to decide how CLUSTER should implement sorting
+ *
+ * tableOid is the OID of a table to be clustered on its index indexOid
+ * (which is already known to be a btree index). Decide whether it's
+ * cheaper to do an indexscan or a seqscan-plus-sort to execute the CLUSTER.
+ * Return true to use sorting, false to use an indexscan.
+ *
+ * Note: caller had better already hold some type of lock on the table.
+ */
+bool
+plan_cluster_use_sort(Oid tableOid, Oid indexOid)
+{
+ PlannerInfo *root;
+ Query *query;
+ PlannerGlobal *glob;
+ RangeTblEntry *rte;
+ RelOptInfo *rel;
+ IndexOptInfo *indexInfo;
+ QualCost indexExprCost;
+ Cost comparisonCost;
+ Path *seqScanPath;
+ Path seqScanAndSortPath;
+ IndexPath *indexScanPath;
+ ListCell *lc;
+
+ /* We can short-circuit the cost comparison if indexscans are disabled */
+ if (!enable_indexscan)
+ return true; /* use sort */
+
+ /* Set up mostly-dummy planner state */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ glob = makeNode(PlannerGlobal);
+
+ root = makeNode(PlannerInfo);
+ root->parse = query;
+ root->glob = glob;
+ root->query_level = 1;
+ root->planner_cxt = CurrentMemoryContext;
+ root->wt_param_id = -1;
+
+ /* Build a minimal RTE for the rel */
+ rte = makeNode(RangeTblEntry);
+ rte->rtekind = RTE_RELATION;
+ rte->relid = tableOid;
+ rte->relkind = RELKIND_RELATION; /* Don't be too picky. */
+ rte->lateral = false;
+ rte->inh = false;
+ rte->inFromCl = true;
+ query->rtable = list_make1(rte);
+
+ /* Set up RTE/RelOptInfo arrays */
+ setup_simple_rel_arrays(root);
+
+ /* Build RelOptInfo */
+ rel = build_simple_rel(root, 1, NULL);
+
+ /* Locate IndexOptInfo for the target index */
+ indexInfo = NULL;
+ foreach(lc, rel->indexlist)
+ {
+ indexInfo = lfirst_node(IndexOptInfo, lc);
+ if (indexInfo->indexoid == indexOid)
+ break;
+ }
+
+ /*
+ * It's possible that get_relation_info did not generate an IndexOptInfo
+ * for the desired index; this could happen if it's not yet reached its
+ * indcheckxmin usability horizon, or if it's a system index and we're
+ * ignoring system indexes. In such cases we should tell CLUSTER to not
+ * trust the index contents but use seqscan-and-sort.
+ */
+ if (lc == NULL) /* not in the list? */
+ return true; /* use sort */
+
+ /*
+ * Rather than doing all the pushups that would be needed to use
+ * set_baserel_size_estimates, just do a quick hack for rows and width.
+ */
+ rel->rows = rel->tuples;
+ rel->reltarget->width = get_relation_data_width(tableOid, NULL);
+
+ root->total_table_pages = rel->pages;
+
+ /*
+ * Determine eval cost of the index expressions, if any. We need to
+ * charge twice that amount for each tuple comparison that happens during
+ * the sort, since tuplesort.c will have to re-evaluate the index
+ * expressions each time. (XXX that's pretty inefficient...)
+ */
+ cost_qual_eval(&indexExprCost, indexInfo->indexprs, root);
+ comparisonCost = 2.0 * (indexExprCost.startup + indexExprCost.per_tuple);
+
+ /* Estimate the cost of seq scan + sort */
+ seqScanPath = create_seqscan_path(root, rel, NULL, 0);
+ cost_sort(&seqScanAndSortPath, root, NIL,
+ seqScanPath->total_cost, rel->tuples, rel->reltarget->width,
+ comparisonCost, maintenance_work_mem, -1.0);
+
+ /* Estimate the cost of index scan */
+ indexScanPath = create_index_path(root, indexInfo,
+ NIL, NIL, NIL, NIL, NIL,
+ ForwardScanDirection, false,
+ NULL, 1.0, false);
+
+ return (seqScanAndSortPath.total_cost < indexScanPath->path.total_cost);
+}
+
+/*
+ * get_partitioned_child_rels
+ * Returns a list of the RT indexes of the partitioned child relations
+ * with rti as the root parent RT index. Also sets
+ * *part_cols_updated to true if any of the root rte's updated
+ * columns is used in the partition key either of the relation whose RTI
+ * is specified or of any child relation.
+ *
+ * Note: This function might get called even for range table entries that
+ * are not partitioned tables; in such a case, it will simply return NIL.
+ */
+List *
+get_partitioned_child_rels(PlannerInfo *root, Index rti,
+ bool *part_cols_updated)
+{
+ List *result = NIL;
+ ListCell *l;
+
+ if (part_cols_updated)
+ *part_cols_updated = false;
+
+ foreach(l, root->pcinfo_list)
{
- Path *subpath = (Path *) lfirst(lc);
- Path *newpath = subpath;
- ListCell *lc1,
- *lc2;
+ PartitionedChildRelInfo *pc = lfirst_node(PartitionedChildRelInfo, l);
- Assert(subpath->param_info == NULL);
- forboth(lc1, targets, lc2, targets_contain_srfs)
+ if (pc->parent_relid == rti)
{
- PathTarget *thistarget = lfirst_node(PathTarget, lc1);
- bool contains_srfs = (bool) lfirst_int(lc2);
-
- /* If this level doesn't contain SRFs, do regular projection */
- if (contains_srfs)
- newpath = (Path *) create_set_projection_path(root,
- rel,
- newpath,
- thistarget);
- else
- {
- /* avoid apply_projection_to_path, in case of multiple refs */
- newpath = (Path *) create_projection_path(root,
- rel,
- newpath,
- thistarget);
- }
+ result = pc->child_rels;
+ if (part_cols_updated)
+ *part_cols_updated = pc->part_cols_updated;
+ break;
}
- lfirst(lc) = newpath;
}
+
+ return result;
}
/*
- * expression_planner
- * Perform planner's transformations on a standalone expression.
- *
- * Various utility commands need to evaluate expressions that are not part
- * of a plannable query. They can do so using the executor's regular
- * expression-execution machinery, but first the expression has to be fed
- * through here to transform it from parser output to something executable.
- *
- * Currently, we disallow sublinks in standalone expressions, so there's no
- * real "planning" involved here. (That might not always be true though.)
- * What we must do is run eval_const_expressions to ensure that any function
- * calls are converted to positional notation and function default arguments
- * get inserted. The fact that constant subexpressions get simplified is a
- * side-effect that is useful when the expression will get evaluated more than
- * once. Also, we must fix operator function IDs.
- *
- * Note: this must not make any damaging changes to the passed-in expression
- * tree. (It would actually be okay to apply fix_opfuncids to it, but since
- * we first do an expression_tree_mutator-based walk, what is returned will
- * be a new node tree.)
+ * get_partitioned_child_rels_for_join
+ * Build and return a list containing the RTI of every partitioned
+ * relation which is a child of some rel included in the join.
*/
-Expr *
-expression_planner(Expr *expr)
+List *
+get_partitioned_child_rels_for_join(PlannerInfo *root, Relids join_relids)
{
- Node *result;
+ List *result = NIL;
+ ListCell *l;
- /*
- * Convert named-argument function calls, insert default arguments and
- * simplify constant subexprs
- */
- result = eval_const_expressions(NULL, (Node *) expr);
+ foreach(l, root->pcinfo_list)
+ {
+ PartitionedChildRelInfo *pc = lfirst(l);
- /* Fill in opfuncid values if missing */
- fix_opfuncids(result);
+ if (bms_is_member(pc->parent_relid, join_relids))
+ result = list_concat(result, list_copy(pc->child_rels));
+ }
- return (Expr *) result;
+ return result;
}
-
/*
- * plan_cluster_use_sort
- * Use the planner to decide how CLUSTER should implement sorting
- *
- * tableOid is the OID of a table to be clustered on its index indexOid
- * (which is already known to be a btree index). Decide whether it's
- * cheaper to do an indexscan or a seqscan-plus-sort to execute the CLUSTER.
- * Return true to use sorting, false to use an indexscan.
+ * add_paths_to_grouping_rel
*
- * Note: caller had better already hold some type of lock on the table.
+ * Add non-partial paths to grouping relation.
*/
-bool
-plan_cluster_use_sort(Oid tableOid, Oid indexOid)
+static void
+add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel, PathTarget *target,
+ PathTarget *partial_grouping_target,
+ const AggClauseCosts *agg_costs,
+ const AggClauseCosts *agg_final_costs,
+ grouping_sets_data *gd, bool can_sort, bool can_hash,
+ double dNumGroups, List *havingQual)
{
- PlannerInfo *root;
- Query *query;
- PlannerGlobal *glob;
- RangeTblEntry *rte;
- RelOptInfo *rel;
- IndexOptInfo *indexInfo;
- QualCost indexExprCost;
- Cost comparisonCost;
- Path *seqScanPath;
- Path seqScanAndSortPath;
- IndexPath *indexScanPath;
+ Query *parse = root->parse;
+ Path *cheapest_path = input_rel->cheapest_total_path;
ListCell *lc;
- /* We can short-circuit the cost comparison if indexscans are disabled */
- if (!enable_indexscan)
- return true; /* use sort */
+ if (can_sort)
+ {
+ /*
+ * Use any available suitably-sorted path as input, and also consider
+ * sorting the cheapest-total path.
+ */
+ foreach(lc, input_rel->pathlist)
+ {
+ Path *path = (Path *) lfirst(lc);
+ bool is_sorted;
- /* Set up mostly-dummy planner state */
- query = makeNode(Query);
- query->commandType = CMD_SELECT;
+ is_sorted = pathkeys_contained_in(root->group_pathkeys,
+ path->pathkeys);
+ if (path == cheapest_path || is_sorted)
+ {
+ /* Sort the cheapest-total path if it isn't already sorted */
+ if (!is_sorted)
+ path = (Path *) create_sort_path(root,
+ grouped_rel,
+ path,
+ root->group_pathkeys,
+ -1.0);
- glob = makeNode(PlannerGlobal);
+ /* Now decide what to stick atop it */
+ if (parse->groupingSets)
+ {
+ consider_groupingsets_paths(root, grouped_rel,
+ path, true, can_hash, target,
+ gd, agg_costs, dNumGroups);
+ }
+ else if (parse->hasAggs)
+ {
+ /*
+ * We have aggregation, possibly with plain GROUP BY. Make
+ * an AggPath.
+ */
+ add_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ path,
+ target,
+ parse->groupClause ? AGG_SORTED : AGG_PLAIN,
+ AGGSPLIT_SIMPLE,
+ parse->groupClause,
+ havingQual,
+ agg_costs,
+ dNumGroups));
+ }
+ else if (parse->groupClause)
+ {
+ /*
+ * We have GROUP BY without aggregation or grouping sets.
+ * Make a GroupPath.
+ */
+ add_path(grouped_rel, (Path *)
+ create_group_path(root,
+ grouped_rel,
+ path,
+ target,
+ parse->groupClause,
+ havingQual,
+ dNumGroups));
+ }
+ else
+ {
+ /* Other cases should have been handled above */
+ Assert(false);
+ }
+ }
+ }
- root = makeNode(PlannerInfo);
- root->parse = query;
- root->glob = glob;
- root->query_level = 1;
- root->planner_cxt = CurrentMemoryContext;
- root->wt_param_id = -1;
+ /*
+ * Now generate a complete GroupAgg Path atop of the cheapest partial
+ * path. We can do this using either Gather or Gather Merge.
+ */
+ if (grouped_rel->partial_pathlist)
+ {
+ Path *path = (Path *) linitial(grouped_rel->partial_pathlist);
+ double total_groups = path->rows * path->parallel_workers;
+
+ path = (Path *) create_gather_path(root,
+ grouped_rel,
+ path,
+ partial_grouping_target,
+ NULL,
+ &total_groups);
+
+ /*
+ * Since Gather's output is always unsorted, we'll need to sort,
+ * unless there's no GROUP BY clause or a degenerate (constant)
+ * one, in which case there will only be a single group.
+ */
+ if (root->group_pathkeys)
+ path = (Path *) create_sort_path(root,
+ grouped_rel,
+ path,
+ root->group_pathkeys,
+ -1.0);
+
+ if (parse->hasAggs)
+ add_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ path,
+ target,
+ parse->groupClause ? AGG_SORTED : AGG_PLAIN,
+ AGGSPLIT_FINAL_DESERIAL,
+ parse->groupClause,
+ havingQual,
+ agg_final_costs,
+ dNumGroups));
+ else
+ add_path(grouped_rel, (Path *)
+ create_group_path(root,
+ grouped_rel,
+ path,
+ target,
+ parse->groupClause,
+ havingQual,
+ dNumGroups));
+
+ /*
+ * The point of using Gather Merge rather than Gather is that it
+ * can preserve the ordering of the input path, so there's no
+ * reason to try it unless (1) it's possible to produce more than
+ * one output row and (2) we want the output path to be ordered.
+ */
+ if (parse->groupClause != NIL && root->group_pathkeys != NIL)
+ {
+ foreach(lc, grouped_rel->partial_pathlist)
+ {
+ Path *subpath = (Path *) lfirst(lc);
+ Path *gmpath;
+ double total_groups;
+
+ /*
+ * It's useful to consider paths that are already properly
+ * ordered for Gather Merge, because those don't need a
+ * sort. It's also useful to consider the cheapest path,
+ * because sorting it in parallel and then doing Gather
+ * Merge may be better than doing an unordered Gather
+ * followed by a sort. But there's no point in considering
+ * non-cheapest paths that aren't already sorted
+ * correctly.
+ */
+ if (path != subpath &&
+ !pathkeys_contained_in(root->group_pathkeys,
+ subpath->pathkeys))
+ continue;
- /* Build a minimal RTE for the rel */
- rte = makeNode(RangeTblEntry);
- rte->rtekind = RTE_RELATION;
- rte->relid = tableOid;
- rte->relkind = RELKIND_RELATION; /* Don't be too picky. */
- rte->lateral = false;
- rte->inh = false;
- rte->inFromCl = true;
- query->rtable = list_make1(rte);
+ total_groups = subpath->rows * subpath->parallel_workers;
- /* Set up RTE/RelOptInfo arrays */
- setup_simple_rel_arrays(root);
+ gmpath = (Path *)
+ create_gather_merge_path(root,
+ grouped_rel,
+ subpath,
+ partial_grouping_target,
+ root->group_pathkeys,
+ NULL,
+ &total_groups);
- /* Build RelOptInfo */
- rel = build_simple_rel(root, 1, NULL);
+ if (parse->hasAggs)
+ add_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ gmpath,
+ target,
+ parse->groupClause ? AGG_SORTED : AGG_PLAIN,
+ AGGSPLIT_FINAL_DESERIAL,
+ parse->groupClause,
+ havingQual,
+ agg_final_costs,
+ dNumGroups));
+ else
+ add_path(grouped_rel, (Path *)
+ create_group_path(root,
+ grouped_rel,
+ gmpath,
+ target,
+ parse->groupClause,
+ havingQual,
+ dNumGroups));
+ }
+ }
+ }
+ }
- /* Locate IndexOptInfo for the target index */
- indexInfo = NULL;
- foreach(lc, rel->indexlist)
+ if (can_hash)
{
- indexInfo = lfirst_node(IndexOptInfo, lc);
- if (indexInfo->indexoid == indexOid)
- break;
- }
+ Size hashaggtablesize;
- /*
- * It's possible that get_relation_info did not generate an IndexOptInfo
- * for the desired index; this could happen if it's not yet reached its
- * indcheckxmin usability horizon, or if it's a system index and we're
- * ignoring system indexes. In such cases we should tell CLUSTER to not
- * trust the index contents but use seqscan-and-sort.
- */
- if (lc == NULL) /* not in the list? */
- return true; /* use sort */
+ if (parse->groupingSets)
+ {
+ /*
+ * Try for a hash-only groupingsets path over unsorted input.
+ */
+ consider_groupingsets_paths(root, grouped_rel,
+ cheapest_path, false, true, target,
+ gd, agg_costs, dNumGroups);
+ }
+ else
+ {
+ hashaggtablesize = estimate_hashagg_tablesize(cheapest_path,
+ agg_costs,
+ dNumGroups);
- /*
- * Rather than doing all the pushups that would be needed to use
- * set_baserel_size_estimates, just do a quick hack for rows and width.
- */
- rel->rows = rel->tuples;
- rel->reltarget->width = get_relation_data_width(tableOid, NULL);
+ /*
+ * Provided that the estimated size of the hashtable does not
+ * exceed work_mem, we'll generate a HashAgg Path, although if we
+ * were unable to sort above, then we'd better generate a Path, so
+ * that we at least have one.
+ */
+ if (hashaggtablesize < work_mem * 1024L ||
+ grouped_rel->pathlist == NIL)
+ {
+ /*
+ * We just need an Agg over the cheapest-total input path,
+ * since input order won't matter.
+ */
+ add_path(grouped_rel, (Path *)
+ create_agg_path(root, grouped_rel,
+ cheapest_path,
+ target,
+ AGG_HASHED,
+ AGGSPLIT_SIMPLE,
+ parse->groupClause,
+ havingQual,
+ agg_costs,
+ dNumGroups));
+ }
+ }
- root->total_table_pages = rel->pages;
+ /*
+ * Generate a HashAgg Path atop of the cheapest partial path. Once
+ * again, we'll only do this if it looks as though the hash table
+ * won't exceed work_mem.
+ */
+ if (grouped_rel->partial_pathlist)
+ {
+ Path *path = (Path *) linitial(grouped_rel->partial_pathlist);
- /*
- * Determine eval cost of the index expressions, if any. We need to
- * charge twice that amount for each tuple comparison that happens during
- * the sort, since tuplesort.c will have to re-evaluate the index
- * expressions each time. (XXX that's pretty inefficient...)
- */
- cost_qual_eval(&indexExprCost, indexInfo->indexprs, root);
- comparisonCost = 2.0 * (indexExprCost.startup + indexExprCost.per_tuple);
+ hashaggtablesize = estimate_hashagg_tablesize(path,
+ agg_final_costs,
+ dNumGroups);
- /* Estimate the cost of seq scan + sort */
- seqScanPath = create_seqscan_path(root, rel, NULL, 0);
- cost_sort(&seqScanAndSortPath, root, NIL,
- seqScanPath->total_cost, rel->tuples, rel->reltarget->width,
- comparisonCost, maintenance_work_mem, -1.0);
+ if (hashaggtablesize < work_mem * 1024L)
+ {
+ double total_groups = path->rows * path->parallel_workers;
- /* Estimate the cost of index scan */
- indexScanPath = create_index_path(root, indexInfo,
- NIL, NIL, NIL, NIL, NIL,
- ForwardScanDirection, false,
- NULL, 1.0, false);
+ path = (Path *) create_gather_path(root,
+ grouped_rel,
+ path,
+ partial_grouping_target,
+ NULL,
+ &total_groups);
- return (seqScanAndSortPath.total_cost < indexScanPath->path.total_cost);
+ add_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ path,
+ target,
+ AGG_HASHED,
+ AGGSPLIT_FINAL_DESERIAL,
+ parse->groupClause,
+ havingQual,
+ agg_final_costs,
+ dNumGroups));
+ }
+ }
+ }
}
/*
- * get_partitioned_child_rels
- * Returns a list of the RT indexes of the partitioned child relations
- * with rti as the root parent RT index. Also sets
- * *part_cols_updated to true if any of the root rte's updated
- * columns is used in the partition key either of the relation whose RTI
- * is specified or of any child relation.
+ * add_partial_paths_to_grouping_rel
*
- * Note: This function might get called even for range table entries that
- * are not partitioned tables; in such a case, it will simply return NIL.
+ * Add partial paths to grouping relation. These paths are not fully
+ * aggregated; a FinalizeAggregate step is still required.
*/
-List *
-get_partitioned_child_rels(PlannerInfo *root, Index rti,
- bool *part_cols_updated)
+static void
+add_partial_paths_to_grouping_rel(PlannerInfo *root,
+ RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel,
+ PathTarget *target,
+ PathTarget *partial_grouping_target,
+ AggClauseCosts *agg_partial_costs,
+ AggClauseCosts *agg_final_costs,
+ grouping_sets_data *gd,
+ bool can_sort,
+ bool can_hash,
+ List *havingQual)
{
- List *result = NIL;
- ListCell *l;
+ Query *parse = root->parse;
+ Path *cheapest_partial_path = linitial(input_rel->partial_pathlist);
+ Size hashaggtablesize;
+ double dNumPartialGroups = 0;
+ ListCell *lc;
- if (part_cols_updated)
- *part_cols_updated = false;
+ /* Estimate number of partial groups. */
+ dNumPartialGroups = get_number_of_groups(root,
+ cheapest_partial_path->rows,
+ gd);
- foreach(l, root->pcinfo_list)
+ if (can_sort)
{
- PartitionedChildRelInfo *pc = lfirst_node(PartitionedChildRelInfo, l);
+ /* This should have been checked previously */
+ Assert(parse->hasAggs || parse->groupClause);
- if (pc->parent_relid == rti)
+ /*
+ * Use any available suitably-sorted path as input, and also consider
+ * sorting the cheapest partial path.
+ */
+ foreach(lc, input_rel->partial_pathlist)
{
- result = pc->child_rels;
- if (part_cols_updated)
- *part_cols_updated = pc->part_cols_updated;
- break;
+ Path *path = (Path *) lfirst(lc);
+ bool is_sorted;
+
+ is_sorted = pathkeys_contained_in(root->group_pathkeys,
+ path->pathkeys);
+ if (path == cheapest_partial_path || is_sorted)
+ {
+ /* Sort the cheapest partial path, if it isn't already */
+ if (!is_sorted)
+ path = (Path *) create_sort_path(root,
+ grouped_rel,
+ path,
+ root->group_pathkeys,
+ -1.0);
+
+ if (parse->hasAggs)
+ add_partial_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ path,
+ partial_grouping_target,
+ parse->groupClause ? AGG_SORTED : AGG_PLAIN,
+ AGGSPLIT_INITIAL_SERIAL,
+ parse->groupClause,
+ NIL,
+ agg_partial_costs,
+ dNumPartialGroups));
+ else
+ add_partial_path(grouped_rel, (Path *)
+ create_group_path(root,
+ grouped_rel,
+ path,
+ partial_grouping_target,
+ parse->groupClause,
+ NIL,
+ dNumPartialGroups));
+ }
}
}
- return result;
+ if (can_hash)
+ {
+ /* Checked above */
+ Assert(parse->hasAggs || parse->groupClause);
+
+ hashaggtablesize =
+ estimate_hashagg_tablesize(cheapest_partial_path,
+ agg_partial_costs,
+ dNumPartialGroups);
+
+ /*
+ * Tentatively produce a partial HashAgg Path, depending on if it
+ * looks as if the hash table will fit in work_mem.
+ */
+ if (hashaggtablesize < work_mem * 1024L)
+ {
+ add_partial_path(grouped_rel, (Path *)
+ create_agg_path(root,
+ grouped_rel,
+ cheapest_partial_path,
+ partial_grouping_target,
+ AGG_HASHED,
+ AGGSPLIT_INITIAL_SERIAL,
+ parse->groupClause,
+ NIL,
+ agg_partial_costs,
+ dNumPartialGroups));
+ }
+ }
}
/*
- * get_partitioned_child_rels_for_join
- * Build and return a list containing the RTI of every partitioned
- * relation which is a child of some rel included in the join.
+ * can_parallel_agg
+ *
+ * Determines whether or not parallel grouping and/or aggregation is possible.
+ * Returns true when possible, false otherwise.
*/
-List *
-get_partitioned_child_rels_for_join(PlannerInfo *root, Relids join_relids)
+static bool
+can_parallel_agg(PlannerInfo *root, RelOptInfo *input_rel,
+ RelOptInfo *grouped_rel, const AggClauseCosts *agg_costs)
{
- List *result = NIL;
- ListCell *l;
+ Query *parse = root->parse;
- foreach(l, root->pcinfo_list)
+ if (!grouped_rel->consider_parallel)
{
- PartitionedChildRelInfo *pc = lfirst(l);
-
- if (bms_is_member(pc->parent_relid, join_relids))
- result = list_concat(result, list_copy(pc->child_rels));
+ /* Not even parallel-safe. */
+ return false;
+ }
+ else if (input_rel->partial_pathlist == NIL)
+ {
+ /* Nothing to use as input for partial aggregate. */
+ return false;
+ }
+ else if (!parse->hasAggs && parse->groupClause == NIL)
+ {
+ /*
+ * We don't know how to do parallel aggregation unless we have either
+ * some aggregates or a grouping clause.
+ */
+ return false;
+ }
+ else if (parse->groupingSets)
+ {
+ /* We don't know how to do grouping sets in parallel. */
+ return false;
+ }
+ else if (agg_costs->hasNonPartial || agg_costs->hasNonSerial)
+ {
+ /* Insufficient support for partial mode. */
+ return false;
}
- return result;
+ /* Everything looks good. */
+ return true;
}
projects / users / gsingh / postgres.git / commitdiff