Split up nested loops.

8 files changed, 46 insertions, 59 deletions

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 8f18a6f00a..7ed03b33a7 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -894,7 +894,7 @@ set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *
 		 bms_membership(root->all_query_rels) != BMS_SINGLETON) &&
 		!(GetTsmRoutine(rte->tablesample->tsmhandler)->repeatable_across_scans))
 	{
-		path = (Path *) create_material_path(rel, path);
+		path = (Path *) create_material_path(rel, path, enable_material);
 	}
 
 	add_path(rel, path);
@@ -3373,12 +3373,16 @@ make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
 		jsa_mask = JSA_FOREIGN;
 		if (enable_hashjoin)
 			jsa_mask |= JSA_HASHJOIN;
-		if (enable_material)
-			jsa_mask |= JSA_NESTLOOP_MATERIALIZE;
 		if (enable_mergejoin)
 			jsa_mask |= JSA_MERGEJOIN;
 		if (enable_nestloop)
-			jsa_mask |= JSA_NESTLOOP;
+		{
+			jsa_mask |= JSA_NESTLOOP_PLAIN;
+			if (enable_material)
+				jsa_mask |= JSA_NESTLOOP_MATERIALIZE;
+			if (enable_memoize)
+				jsa_mask |= JSA_NESTLOOP_MEMOIZE;
+		}
 		if (enable_partitionwise_join)
 			jsa_mask |= JSA_PARTITIONWISE;
 
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 19717a5324..38ad8fb50e 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -2481,7 +2481,7 @@ cost_merge_append(Path *path, PlannerInfo *root,
  */
 void
 cost_material(Path *path,
-			  int input_disabled_nodes,
+			  bool enabled, int input_disabled_nodes,
 			  Cost input_startup_cost, Cost input_total_cost,
 			  double tuples, int width)
 {
@@ -2519,7 +2519,7 @@ cost_material(Path *path,
 		run_cost += seq_page_cost * npages;
 	}
 
-	path->disabled_nodes = input_disabled_nodes + (enable_material ? 0 : 1);
+	path->disabled_nodes = input_disabled_nodes + (enabled ? 0 : 1);
 	path->startup_cost = startup_cost;
 	path->total_cost = startup_cost + run_cost;
 }
@@ -3266,7 +3266,7 @@ cost_group(Path *path, PlannerInfo *root,
  */
 void
 initial_cost_nestloop(PlannerInfo *root, JoinCostWorkspace *workspace,
-					  JoinType jointype,
+					  JoinType jointype, unsigned nestloop_subtype,
 					  Path *outer_path, Path *inner_path,
 					  JoinPathExtraData *extra)
 {
@@ -3280,7 +3280,7 @@ initial_cost_nestloop(PlannerInfo *root, JoinCostWorkspace *workspace,
 	Cost		inner_rescan_run_cost;
 
 	/* Count up disabled nodes. */
-	disabled_nodes = (extra->jsa_mask & JSA_NESTLOOP) == 0 ? 1 : 0;
+	disabled_nodes = (extra->jsa_mask & nestloop_subtype) == 0 ? 1 : 0;
 	disabled_nodes += inner_path->disabled_nodes;
 	disabled_nodes += outer_path->disabled_nodes;
 
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c
index 4fa6c3d918..d853e2a64e 100644
--- a/src/backend/optimizer/path/joinpath.c
+++ b/src/backend/optimizer/path/joinpath.c
@@ -862,6 +862,7 @@ try_nestloop_path(PlannerInfo *root,
 				  Path *inner_path,
 				  List *pathkeys,
 				  JoinType jointype,
+				  unsigned nestloop_subtype,
 				  JoinPathExtraData *extra)
 {
 	Relids		required_outer;
@@ -946,7 +947,7 @@ try_nestloop_path(PlannerInfo *root,
 	 * The latter two steps are expensive enough to make this two-phase
 	 * methodology worthwhile.
 	 */
-	initial_cost_nestloop(root, &workspace, jointype,
+	initial_cost_nestloop(root, &workspace, jointype, nestloop_subtype,
 						  outer_path, inner_path, extra);
 
 	if (add_path_precheck(joinrel, workspace.disabled_nodes,
@@ -984,6 +985,7 @@ try_partial_nestloop_path(PlannerInfo *root,
 						  Path *inner_path,
 						  List *pathkeys,
 						  JoinType jointype,
+						  unsigned nestloop_subtype,
 						  JoinPathExtraData *extra)
 {
 	JoinCostWorkspace workspace;
@@ -1031,7 +1033,7 @@ try_partial_nestloop_path(PlannerInfo *root,
 	 * Before creating a path, get a quick lower bound on what it is likely to
 	 * cost.  Bail out right away if it looks terrible.
 	 */
-	initial_cost_nestloop(root, &workspace, jointype,
+	initial_cost_nestloop(root, &workspace, jointype, nestloop_subtype,
 						  outer_path, inner_path, extra);
 	if (!add_partial_path_precheck(joinrel, workspace.disabled_nodes,
 								   workspace.total_cost, pathkeys))
@@ -1939,17 +1941,8 @@ match_unsorted_outer(PlannerInfo *root,
 		if ((extra->jsa_mask & JSA_NESTLOOP_MATERIALIZE) != 0 &&
 			inner_cheapest_total != NULL &&
 			!ExecMaterializesOutput(inner_cheapest_total->pathtype))
-		{
 			matpath = (Path *)
-				create_material_path(innerrel, inner_cheapest_total);
-
-			/*
-			 * Ignore create_material_path()'s idea of whether the path is
-			 * disabled in general; JSA_NESTLOOP_MATERIALIZE means it is
-			 * acceptable here.
-			 */
-			matpath->disabled_nodes = inner_cheapest_total->disabled_nodes;
-		}
+				create_material_path(innerrel, inner_cheapest_total, true);
 	}
 
 	foreach(lc1, outerrel->pathlist)
@@ -1997,6 +1990,7 @@ match_unsorted_outer(PlannerInfo *root,
 							  inner_cheapest_total,
 							  merge_pathkeys,
 							  jointype,
+							  JSA_NESTLOOP_PLAIN,
 							  extra);
 		}
 		else if (nestjoinOK)
@@ -2020,6 +2014,7 @@ match_unsorted_outer(PlannerInfo *root,
 								  innerpath,
 								  merge_pathkeys,
 								  jointype,
+								  JSA_NESTLOOP_PLAIN,
 								  extra);
 
 				/*
@@ -2036,6 +2031,7 @@ match_unsorted_outer(PlannerInfo *root,
 									  mpath,
 									  merge_pathkeys,
 									  jointype,
+									  JSA_NESTLOOP_MEMOIZE,
 									  extra);
 			}
 
@@ -2047,6 +2043,7 @@ match_unsorted_outer(PlannerInfo *root,
 								  matpath,
 								  merge_pathkeys,
 								  jointype,
+								  JSA_NESTLOOP_MATERIALIZE,
 								  extra);
 		}
 
@@ -2188,18 +2185,8 @@ consider_parallel_nestloop(PlannerInfo *root,
 		inner_cheapest_total->parallel_safe &&
 		!PATH_PARAM_BY_REL(inner_cheapest_total, outerrel) &&
 		!ExecMaterializesOutput(inner_cheapest_total->pathtype))
-	{
 		matpath = (Path *)
-			create_material_path(innerrel, inner_cheapest_total);
-		Assert(matpath->parallel_safe);
-
-		/*
-		 * Ignore create_material_path()'s idea of whether the path is
-		 * disabled in general; JSA_NESTLOOP_MATERIALIZE means it is
-		 * acceptable here.
-		 */
-		matpath->disabled_nodes = inner_cheapest_total->disabled_nodes;
-	}
+			create_material_path(innerrel, inner_cheapest_total, true);
 
 	foreach(lc1, outerrel->partial_pathlist)
 	{
@@ -2244,7 +2231,8 @@ consider_parallel_nestloop(PlannerInfo *root,
 			}
 
 			try_partial_nestloop_path(root, joinrel, outerpath, innerpath,
-									  pathkeys, jointype, extra);
+									  pathkeys, jointype, JSA_NESTLOOP_PLAIN,
+									  extra);
 
 			/*
 			 * Try generating a memoize path and see if that makes the nested
@@ -2255,13 +2243,15 @@ consider_parallel_nestloop(PlannerInfo *root,
 									 extra);
 			if (mpath != NULL)
 				try_partial_nestloop_path(root, joinrel, outerpath, mpath,
-										  pathkeys, jointype, extra);
+										  pathkeys, jointype,
+										  JSA_NESTLOOP_MEMOIZE, extra);
 		}
 
 		/* Also consider materialized form of the cheapest inner path */
 		if (matpath != NULL)
 			try_partial_nestloop_path(root, joinrel, outerpath, matpath,
-									  pathkeys, jointype, extra);
+									  pathkeys, jointype,
+									  JSA_NESTLOOP_MATERIALIZE, extra);
 	}
 }
 
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 8e0e5977a9..7372232b81 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -6550,6 +6550,7 @@ materialize_finished_plan(Plan *subplan)
 
 	/* Set cost data */
 	cost_material(&matpath,
+				  enable_material,
 				  subplan->disabled_nodes,
 				  subplan->startup_cost,
 				  subplan->total_cost,
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index fc97bf6ee2..a704d0cd7b 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -1631,7 +1631,7 @@ create_group_result_path(PlannerInfo *root, RelOptInfo *rel,
  *	  pathnode.
  */
 MaterialPath *
-create_material_path(RelOptInfo *rel, Path *subpath)
+create_material_path(RelOptInfo *rel, Path *subpath, bool enabled)
 {
 	MaterialPath *pathnode = makeNode(MaterialPath);
 
@@ -1650,6 +1650,7 @@ create_material_path(RelOptInfo *rel, Path *subpath)
 	pathnode->subpath = subpath;
 
 	cost_material(&pathnode->path,
+				  enabled,
 				  subpath->disabled_nodes,
 				  subpath->startup_cost,
 				  subpath->total_cost,
@@ -4158,7 +4159,8 @@ reparameterize_path(PlannerInfo *root, Path *path,
 											loop_count);
 				if (spath == NULL)
 					return NULL;
-				return (Path *) create_material_path(rel, spath);
+				return (Path *) create_material_path(rel, spath,
+													 enable_material);
 			}
 		case T_Memoize:
 			{
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index 854a782944..071a8749cf 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -125,7 +125,7 @@ extern void cost_merge_append(Path *path, PlannerInfo *root,
 							  Cost input_startup_cost, Cost input_total_cost,
 							  double tuples);
 extern void cost_material(Path *path,
-						  int input_disabled_nodes,
+						  bool enabled, int input_disabled_nodes,
 						  Cost input_startup_cost, Cost input_total_cost,
 						  double tuples, int width);
 extern void cost_agg(Path *path, PlannerInfo *root,
@@ -148,7 +148,7 @@ extern void cost_group(Path *path, PlannerInfo *root,
 					   double input_tuples);
 extern void initial_cost_nestloop(PlannerInfo *root,
 								  JoinCostWorkspace *workspace,
-								  JoinType jointype,
+								  JoinType jointype, unsigned nestloop_subtype,
 								  Path *outer_path, Path *inner_path,
 								  JoinPathExtraData *extra);
 extern void final_cost_nestloop(PlannerInfo *root, NestPath *path,
diff --git a/src/include/optimizer/pathnode.h b/src/include/optimizer/pathnode.h
index 266c551cac..ed2e3a1c8b 100644
--- a/src/include/optimizer/pathnode.h
+++ b/src/include/optimizer/pathnode.h
@@ -82,7 +82,8 @@ extern GroupResultPath *create_group_result_path(PlannerInfo *root,
 												 RelOptInfo *rel,
 												 PathTarget *target,
 												 List *havingqual);
-extern MaterialPath *create_material_path(RelOptInfo *rel, Path *subpath);
+extern MaterialPath *create_material_path(RelOptInfo *rel, Path *subpath,
+										  bool enabled);
 extern MemoizePath *create_memoize_path(PlannerInfo *root,
 										RelOptInfo *rel,
 										Path *subpath,
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 4177d7a45a..94779eff9a 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -25,30 +25,19 @@
  * mask is computed on the basis of the various enable_* GUCs, and can be
  * overriden by hooks.
  *
- * JSA_FOREIGN means that it's OK for a FDW to produce join paths.
- *
- * JSA_MERGEJOIN means that a mergejoin is OK.
- *
- * JSA_NESTLOOP means that a nested loop is OK in general.
- *
- * JSA_NESTLOOP_MATERIALIZE and JSA_NESTLOOP_NO_MATERIALIZE mean that it's
- * OK for a nested loop to materialize or not materialize the inner side.
- * JSA_NESTLOOP_MEMOIZE and JSA_NESTLOOP_NO_MEMOIZE mean that it's OK for
- * a nested loop to memoize or not memoize the inner side.
- *
- * JSA_HASHJOIN means that a hash join is OK.
- *
- * JSA_PARTITIONWISE means that a partitionwise join is OK.
+ * We have five main join strategie: a foreign join (when supported by the
+ * relevant FDW), a merge join, a nested loop, a hash join, and a partitionwise
+ * join. Nested loops are further subdivided depending on whether the inner
+ * side of the join is materialized, memoized, or neither (which we here call
+ * a "plain" nested loop).
  */
 #define JSA_FOREIGN						0x0001
 #define JSA_MERGEJOIN					0x0002
-#define JSA_NESTLOOP					0x0004
+#define JSA_NESTLOOP_PLAIN				0x0004
 #define JSA_NESTLOOP_MATERIALIZE		0x0008
-#define JSA_NESTLOOP_NO_MATERIALIZE		0x0010
-#define JSA_NESTLOOP_MEMOIZE			0x0020
-#define JSA_NESTLOOP_NO_MEMOIZE			0x0040
-#define JSA_HASHJOIN					0x0080
-#define JSA_PARTITIONWISE				0x0100
+#define JSA_NESTLOOP_MEMOIZE			0x0010
+#define JSA_HASHJOIN					0x0020
+#define JSA_PARTITIONWISE				0x0040
 
 /*
  * allpaths.c