Change NestPath node to contain JoinPath node

This makes the structure of all JoinPath-derived nodes the same,
independent of whether they have additional fields.

Discussion: https://www.postgresql.org/message-id/flat/c1097590-a6a4-486a-64b1-e1f9cc0533ce@enterprisedb.com

Author: petere

src/backend/optimizer/path/costsize.c

@@ -167,7 +167,7 @@ static bool cost_qual_eval_walker(Node *node, cost_qual_eval_context *context);
 static void get_restriction_qual_cost(PlannerInfo *root, RelOptInfo *baserel,
 									  ParamPathInfo *param_info,
 									  QualCost *qpqual_cost);
-static bool has_indexed_join_quals(NestPath *joinpath);
+static bool has_indexed_join_quals(NestPath *path);
 static double approx_tuple_count(PlannerInfo *root, JoinPath *path,
 								 List *quals);
 static double calc_joinrel_size_estimate(PlannerInfo *root,
@@ -2978,8 +2978,8 @@ final_cost_nestloop(PlannerInfo *root, NestPath *path,
 					JoinCostWorkspace *workspace,
 					JoinPathExtraData *extra)
 {
-	Path	   *outer_path = path->outerjoinpath;
-	Path	   *inner_path = path->innerjoinpath;
+	Path	   *outer_path = path->jpath.outerjoinpath;
+	Path	   *inner_path = path->jpath.innerjoinpath;
 	double		outer_path_rows = outer_path->rows;
 	double		inner_path_rows = inner_path->rows;
 	Cost		startup_cost = workspace->startup_cost;
@@ -2994,18 +2994,18 @@ final_cost_nestloop(PlannerInfo *root, NestPath *path,
 	if (inner_path_rows <= 0)
 		inner_path_rows = 1;
 	/* Mark the path with the correct row estimate */
-	if (path->path.param_info)
-		path->path.rows = path->path.param_info->ppi_rows;
+	if (path->jpath.path.param_info)
+		path->jpath.path.rows = path->jpath.path.param_info->ppi_rows;
 	else
-		path->path.rows = path->path.parent->rows;
+		path->jpath.path.rows = path->jpath.path.parent->rows;
 
 	/* For partial paths, scale row estimate. */
-	if (path->path.parallel_workers > 0)
+	if (path->jpath.path.parallel_workers > 0)
 	{
-		double		parallel_divisor = get_parallel_divisor(&path->path);
+		double		parallel_divisor = get_parallel_divisor(&path->jpath.path);
 
-		path->path.rows =
-			clamp_row_est(path->path.rows / parallel_divisor);
+		path->jpath.path.rows =
+			clamp_row_est(path->jpath.path.rows / parallel_divisor);
 	}
 
 	/*
@@ -3018,7 +3018,7 @@ final_cost_nestloop(PlannerInfo *root, NestPath *path,
 
 	/* cost of inner-relation source data (we already dealt with outer rel) */
 
-	if (path->jointype == JOIN_SEMI || path->jointype == JOIN_ANTI ||
+	if (path->jpath.jointype == JOIN_SEMI || path->jpath.jointype == JOIN_ANTI ||
 		extra->inner_unique)
 	{
 		/*
@@ -3136,17 +3136,17 @@ final_cost_nestloop(PlannerInfo *root, NestPath *path,
 	}
 
 	/* CPU costs */
-	cost_qual_eval(&restrict_qual_cost, path->joinrestrictinfo, root);
+	cost_qual_eval(&restrict_qual_cost, path->jpath.joinrestrictinfo, root);
 	startup_cost += restrict_qual_cost.startup;
 	cpu_per_tuple = cpu_tuple_cost + restrict_qual_cost.per_tuple;
 	run_cost += cpu_per_tuple * ntuples;
 
 	/* tlist eval costs are paid per output row, not per tuple scanned */
-	startup_cost += path->path.pathtarget->cost.startup;
-	run_cost += path->path.pathtarget->cost.per_tuple * path->path.rows;
+	startup_cost += path->jpath.path.pathtarget->cost.startup;
+	run_cost += path->jpath.path.pathtarget->cost.per_tuple * path->jpath.path.rows;
 
-	path->path.startup_cost = startup_cost;
-	path->path.total_cost = startup_cost + run_cost;
+	path->jpath.path.startup_cost = startup_cost;
+	path->jpath.path.total_cost = startup_cost + run_cost;
 }
 
 /*
@@ -4771,8 +4771,9 @@ compute_semi_anti_join_factors(PlannerInfo *root,
  * expensive.
  */
 static bool
-has_indexed_join_quals(NestPath *joinpath)
+has_indexed_join_quals(NestPath *path)
 {
+	JoinPath   *joinpath = &path->jpath;
 	Relids		joinrelids = joinpath->path.parent->relids;
 	Path	   *innerpath = joinpath->innerjoinpath;
 	List	   *indexclauses;

src/backend/optimizer/plan/createplan.c

@@ -4221,22 +4221,22 @@ create_nestloop_plan(PlannerInfo *root,
 	NestLoop   *join_plan;
 	Plan	   *outer_plan;
 	Plan	   *inner_plan;
-	List	   *tlist = build_path_tlist(root, &best_path->path);
-	List	   *joinrestrictclauses = best_path->joinrestrictinfo;
+	List	   *tlist = build_path_tlist(root, &best_path->jpath.path);
+	List	   *joinrestrictclauses = best_path->jpath.joinrestrictinfo;
 	List	   *joinclauses;
 	List	   *otherclauses;
 	Relids		outerrelids;
 	List	   *nestParams;
 	Relids		saveOuterRels = root->curOuterRels;
 
 	/* NestLoop can project, so no need to be picky about child tlists */
-	outer_plan = create_plan_recurse(root, best_path->outerjoinpath, 0);
+	outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath, 0);
 
 	/* For a nestloop, include outer relids in curOuterRels for inner side */
 	root->curOuterRels = bms_union(root->curOuterRels,
-								   best_path->outerjoinpath->parent->relids);
+								   best_path->jpath.outerjoinpath->parent->relids);
 
-	inner_plan = create_plan_recurse(root, best_path->innerjoinpath, 0);
+	inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath, 0);
 
 	/* Restore curOuterRels */
 	bms_free(root->curOuterRels);
@@ -4247,10 +4247,10 @@ create_nestloop_plan(PlannerInfo *root,
 
 	/* Get the join qual clauses (in plain expression form) */
 	/* Any pseudoconstant clauses are ignored here */
-	if (IS_OUTER_JOIN(best_path->jointype))
+	if (IS_OUTER_JOIN(best_path->jpath.jointype))
 	{
 		extract_actual_join_clauses(joinrestrictclauses,
-									best_path->path.parent->relids,
+									best_path->jpath.path.parent->relids,
 									&joinclauses, &otherclauses);
 	}
 	else
@@ -4261,7 +4261,7 @@ create_nestloop_plan(PlannerInfo *root,
 	}
 
 	/* Replace any outer-relation variables with nestloop params */
-	if (best_path->path.param_info)
+	if (best_path->jpath.path.param_info)
 	{
 		joinclauses = (List *)
 			replace_nestloop_params(root, (Node *) joinclauses);
@@ -4273,7 +4273,7 @@ create_nestloop_plan(PlannerInfo *root,
 	 * Identify any nestloop parameters that should be supplied by this join
 	 * node, and remove them from root->curOuterParams.
 	 */
-	outerrelids = best_path->outerjoinpath->parent->relids;
+	outerrelids = best_path->jpath.outerjoinpath->parent->relids;
 	nestParams = identify_current_nestloop_params(root, outerrelids);
 
 	join_plan = make_nestloop(tlist,
@@ -4282,10 +4282,10 @@ create_nestloop_plan(PlannerInfo *root,
 							  nestParams,
 							  outer_plan,
 							  inner_plan,
-							  best_path->jointype,
-							  best_path->inner_unique);
+							  best_path->jpath.jointype,
+							  best_path->jpath.inner_unique);
 
-	copy_generic_path_info(&join_plan->join.plan, &best_path->path);
+	copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
 
 	return join_plan;
 }

src/backend/optimizer/util/pathnode.c

@@ -2443,28 +2443,28 @@ create_nestloop_path(PlannerInfo *root,
 		restrict_clauses = jclauses;
 	}
 
-	pathnode->path.pathtype = T_NestLoop;
-	pathnode->path.parent = joinrel;
-	pathnode->path.pathtarget = joinrel->reltarget;
-	pathnode->path.param_info =
+	pathnode->jpath.path.pathtype = T_NestLoop;
+	pathnode->jpath.path.parent = joinrel;
+	pathnode->jpath.path.pathtarget = joinrel->reltarget;
+	pathnode->jpath.path.param_info =
 		get_joinrel_parampathinfo(root,
 								  joinrel,
 								  outer_path,
 								  inner_path,
 								  extra->sjinfo,
 								  required_outer,
 								  &restrict_clauses);
-	pathnode->path.parallel_aware = false;
-	pathnode->path.parallel_safe = joinrel->consider_parallel &&
+	pathnode->jpath.path.parallel_aware = false;
+	pathnode->jpath.path.parallel_safe = joinrel->consider_parallel &&
 		outer_path->parallel_safe && inner_path->parallel_safe;
 	/* This is a foolish way to estimate parallel_workers, but for now... */
-	pathnode->path.parallel_workers = outer_path->parallel_workers;
-	pathnode->path.pathkeys = pathkeys;
-	pathnode->jointype = jointype;
-	pathnode->inner_unique = extra->inner_unique;
-	pathnode->outerjoinpath = outer_path;
-	pathnode->innerjoinpath = inner_path;
-	pathnode->joinrestrictinfo = restrict_clauses;
+	pathnode->jpath.path.parallel_workers = outer_path->parallel_workers;
+	pathnode->jpath.path.pathkeys = pathkeys;
+	pathnode->jpath.jointype = jointype;
+	pathnode->jpath.inner_unique = extra->inner_unique;
+	pathnode->jpath.outerjoinpath = outer_path;
+	pathnode->jpath.innerjoinpath = inner_path;
+	pathnode->jpath.joinrestrictinfo = restrict_clauses;
 
 	final_cost_nestloop(root, pathnode, workspace, extra);
 
@@ -4110,13 +4110,15 @@ do { \
 		case T_NestPath:
 			{
 				JoinPath   *jpath;
+				NestPath   *npath;
 
-				FLAT_COPY_PATH(jpath, path, NestPath);
+				FLAT_COPY_PATH(npath, path, NestPath);
 
+				jpath = (JoinPath *) npath;
 				REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath);
 				REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath);
 				ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo);
-				new_path = (Path *) jpath;
+				new_path = (Path *) npath;
 			}
 			break;
 

src/include/nodes/pathnodes.h

@@ -1598,7 +1598,10 @@ typedef struct JoinPath
  * A nested-loop path needs no special fields.
  */
 
-typedef JoinPath NestPath;
+typedef struct NestPath
+{
+	JoinPath	jpath;
+} NestPath;
 
 /*
  * A mergejoin path has these fields.