Fix testing with WRITE_READ_PARSE_PLAN_TREES.

Change RestrictInfo to AQOClause.
Add AQOConstNode to use it instead of useless nodes.
Serialize/deserialize all AQOPlanNode and AQOConstNode fields.

aqo_pg13.patch

@@ -1,5 +1,5 @@
 diff --git a/contrib/Makefile b/contrib/Makefile
-index 1846d415b6..95519ac11d 100644
+index 1846d415b6f..95519ac11de 100644
 --- a/contrib/Makefile
 +++ b/contrib/Makefile
 @@ -7,6 +7,7 @@ include $(top_builddir)/src/Makefile.global
@@ -11,7 +11,7 @@ index 1846d415b6..95519ac11d 100644
  		auto_explain	\
  		bloom		\
 diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
-index bc05c96b4c..b6a3abe0d2 100644
+index bc05c96b4ce..b6a3abe0d2b 100644
 --- a/src/backend/commands/explain.c
 +++ b/src/backend/commands/explain.c
 @@ -24,6 +24,7 @@
@@ -57,7 +57,7 @@ index bc05c96b4c..b6a3abe0d2 100644
  	if (es->format == EXPLAIN_FORMAT_TEXT)
  		appendStringInfoChar(es->str, '\n');
 diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
-index 692b6c1559..580d04d784 100644
+index 692b6c1559f..580d04d7844 100644
 --- a/src/backend/nodes/copyfuncs.c
 +++ b/src/backend/nodes/copyfuncs.c
 @@ -132,6 +132,7 @@ CopyPlanFields(const Plan *from, Plan *newnode)
@@ -69,35 +69,31 @@ index 692b6c1559..580d04d784 100644
 
  /*
 diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
-index 21ececf0c2..a0e7a7ebca 100644
+index 21ececf0c2f..ebfd3ba86de 100644
 --- a/src/backend/nodes/outfuncs.c
 +++ b/src/backend/nodes/outfuncs.c
 @@ -342,6 +342,7 @@ _outPlanInfo(StringInfo str, const Plan *node)
  	WRITE_NODE_FIELD(initPlan);
  	WRITE_BITMAPSET_FIELD(extParam);
  	WRITE_BITMAPSET_FIELD(allParam);
-+	/*WRITE_NODE_FIELD(ext_nodes); */
++	WRITE_NODE_FIELD(ext_nodes);
  }
 
  /*
 diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
-index 7976b369ba..604314e0b3 100644
+index 7976b369ba8..2e47bd8d950 100644
 --- a/src/backend/nodes/readfuncs.c
 +++ b/src/backend/nodes/readfuncs.c
-@@ -1580,6 +1580,11 @@ ReadCommonPlan(Plan *local_node)
+@@ -1580,6 +1580,7 @@ ReadCommonPlan(Plan *local_node)
  	READ_NODE_FIELD(initPlan);
  	READ_BITMAPSET_FIELD(extParam);
  	READ_BITMAPSET_FIELD(allParam);
-+	local_node->ext_nodes = NIL;
-+	/* READ_NODE_FIELD(ext_nodes);
-+	 * Don't serialize this field. It is required to serialize RestrictInfo and
-+	 * EqualenceClass.
-+	*/
++	READ_NODE_FIELD(ext_nodes);
  }
 
  /*
 diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
-index 4edc859cb5..988f2e6ab7 100644
+index 4edc859cb57..988f2e6ab75 100644
 --- a/src/backend/optimizer/path/costsize.c
 +++ b/src/backend/optimizer/path/costsize.c
 @@ -98,6 +98,12 @@
@@ -363,7 +359,7 @@ index 4edc859cb5..988f2e6ab7 100644
  {
  	double		parallel_divisor = path->parallel_workers;
 diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
-index 917713c163..5b7bf1cec6 100644
+index 917713c1633..5b7bf1cec69 100644
 --- a/src/backend/optimizer/plan/createplan.c
 +++ b/src/backend/optimizer/plan/createplan.c
 @@ -70,6 +70,7 @@
@@ -394,7 +390,7 @@ index 917713c163..5b7bf1cec6 100644
 
  /*
 diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
-index 27c665ac12..f599fba755 100644
+index 821693c60ee..fa627f472f9 100644
 --- a/src/backend/optimizer/plan/planner.c
 +++ b/src/backend/optimizer/plan/planner.c
 @@ -145,7 +145,8 @@ static List *extract_rollup_sets(List *groupingSets);
@@ -407,7 +403,7 @@ index 27c665ac12..f599fba755 100644
  								   grouping_sets_data *gd,
  								   List *target_list);
  static RelOptInfo *create_grouping_paths(PlannerInfo *root,
-@@ -3686,7 +3687,8 @@ standard_qp_callback(PlannerInfo *root, void *extra)
+@@ -3682,7 +3683,8 @@ standard_qp_callback(PlannerInfo *root, void *extra)
   */
  static double
  get_number_of_groups(PlannerInfo *root,
@@ -417,7 +413,7 @@ index 27c665ac12..f599fba755 100644
  					 grouping_sets_data *gd,
  					 List *target_list)
  {
-@@ -3723,7 +3725,7 @@ get_number_of_groups(PlannerInfo *root,
+@@ -3719,7 +3721,7 @@ get_number_of_groups(PlannerInfo *root,
  					GroupingSetData *gs = lfirst_node(GroupingSetData, lc2);
  					double		numGroups = estimate_num_groups(root,
  																groupExprs,
@@ -426,7 +422,7 @@ index 27c665ac12..f599fba755 100644
  																&gset);
 
  					gs->numGroups = numGroups;
-@@ -3748,7 +3750,7 @@ get_number_of_groups(PlannerInfo *root,
+@@ -3744,7 +3746,7 @@ get_number_of_groups(PlannerInfo *root,
  					GroupingSetData *gs = lfirst_node(GroupingSetData, lc2);
  					double		numGroups = estimate_num_groups(root,
  																groupExprs,
@@ -435,7 +431,7 @@ index 27c665ac12..f599fba755 100644
  																&gset);
 
  					gs->numGroups = numGroups;
-@@ -3764,8 +3766,8 @@ get_number_of_groups(PlannerInfo *root,
+@@ -3760,8 +3762,8 @@ get_number_of_groups(PlannerInfo *root,
  			groupExprs = get_sortgrouplist_exprs(parse->groupClause,
  												 target_list);
 
@@ -446,7 +442,7 @@ index 27c665ac12..f599fba755 100644
  		}
  	}
  	else if (parse->groupingSets)
-@@ -4151,7 +4153,8 @@ create_ordinary_grouping_paths(PlannerInfo *root, RelOptInfo *input_rel,
+@@ -4147,7 +4149,8 @@ create_ordinary_grouping_paths(PlannerInfo *root, RelOptInfo *input_rel,
  	 * Estimate number of groups.
  	 */
  	dNumGroups = get_number_of_groups(root,
@@ -456,7 +452,7 @@ index 27c665ac12..f599fba755 100644
  									  gd,
  									  extra->targetList);
 
-@@ -6935,13 +6938,15 @@ create_partial_grouping_paths(PlannerInfo *root,
+@@ -6931,13 +6934,15 @@ create_partial_grouping_paths(PlannerInfo *root,
  	if (cheapest_total_path != NULL)
  		dNumPartialGroups =
  			get_number_of_groups(root,
@@ -475,7 +471,7 @@ index 27c665ac12..f599fba755 100644
  								 extra->targetList);
 
 diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
-index a203e6f1ff..d31bf5bae6 100644
+index a203e6f1ff5..d31bf5bae63 100644
 --- a/src/backend/optimizer/util/relnode.c
 +++ b/src/backend/optimizer/util/relnode.c
 @@ -258,6 +258,7 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptInfo *parent)
@@ -541,7 +537,7 @@ index a203e6f1ff..d31bf5bae6 100644
 
  	return ppi;
 diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
-index 37458da096..248a1875a1 100644
+index 37458da096d..248a1875a18 100644
 --- a/src/backend/utils/adt/selfuncs.c
 +++ b/src/backend/utils/adt/selfuncs.c
 @@ -147,6 +147,7 @@
@@ -573,7 +569,7 @@ index 37458da096..248a1875a1 100644
   * estimate_num_groups		- Estimate number of groups in a grouped query
   *
 diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
-index ba661d32a6..09d0abe58b 100644
+index ba661d32a63..09d0abe58be 100644
 --- a/src/include/commands/explain.h
 +++ b/src/include/commands/explain.h
 @@ -75,6 +75,18 @@ extern PGDLLIMPORT ExplainOneQuery_hook_type ExplainOneQuery_hook;
@@ -596,7 +592,7 @@ index ba661d32a6..09d0abe58b 100644
  extern void ExplainQuery(ParseState *pstate, ExplainStmt *stmt,
  						 ParamListInfo params, DestReceiver *dest);
 diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
-index 5ebf070979..5b2acd7de2 100644
+index d2b4271de9d..559b9db7121 100644
 --- a/src/include/nodes/pathnodes.h
 +++ b/src/include/nodes/pathnodes.h
 @@ -739,6 +739,10 @@ typedef struct RelOptInfo
@@ -635,7 +631,7 @@ index 5ebf070979..5b2acd7de2 100644
 
 
 diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
-index 90f02ce6fd..88c332164d 100644
+index 90f02ce6fdd..88c332164dd 100644
 --- a/src/include/nodes/plannodes.h
 +++ b/src/include/nodes/plannodes.h
 @@ -159,6 +159,9 @@ typedef struct Plan
@@ -649,7 +645,7 @@ index 90f02ce6fd..88c332164d 100644
 
  /* ----------------
 diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
-index 6141654e47..e6b28cbb05 100644
+index 6141654e478..e6b28cbb05f 100644
 --- a/src/include/optimizer/cost.h
 +++ b/src/include/optimizer/cost.h
 @@ -39,6 +39,37 @@ typedef enum
@@ -733,7 +729,7 @@ index 6141654e47..e6b28cbb05 100644
 
  #endif							/* COST_H */
 diff --git a/src/include/optimizer/pathnode.h b/src/include/optimizer/pathnode.h
-index 3bd7072ae8..21bbaba11c 100644
+index 3bd7072ae8c..21bbaba11c8 100644
 --- a/src/include/optimizer/pathnode.h
 +++ b/src/include/optimizer/pathnode.h
 @@ -18,6 +18,10 @@
@@ -748,7 +744,7 @@ index 3bd7072ae8..21bbaba11c 100644
   * prototypes for pathnode.c
   */
 diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
-index 8ce60e202e..75415102c2 100644
+index 8ce60e202e5..75415102c2e 100644
 --- a/src/include/optimizer/planmain.h
 +++ b/src/include/optimizer/planmain.h
 @@ -24,6 +24,12 @@ extern double cursor_tuple_fraction;
@@ -765,7 +761,7 @@ index 8ce60e202e..75415102c2 100644
   * prototypes for plan/planmain.c
   */
 diff --git a/src/include/utils/selfuncs.h b/src/include/utils/selfuncs.h
-index 7ac4a06391..def3522881 100644
+index 7ac4a063915..74fe91b89f1 100644
 --- a/src/include/utils/selfuncs.h
 +++ b/src/include/utils/selfuncs.h
 @@ -127,6 +127,12 @@ typedef bool (*get_index_stats_hook_type) (PlannerInfo *root,
@@ -781,13 +777,13 @@ index 7ac4a06391..def3522881 100644
 
  /* Functions in selfuncs.c */
 
-@@ -195,6 +201,9 @@ extern void mergejoinscansel(PlannerInfo *root, Node *clause,
+@@ -193,6 +199,9 @@ extern void mergejoinscansel(PlannerInfo *root, Node *clause,
+ 							 Selectivity *leftstart, Selectivity *leftend,
+ 							 Selectivity *rightstart, Selectivity *rightend);
 
- extern double estimate_num_groups(PlannerInfo *root, List *groupExprs,
- 								  double input_rows, List **pgset);
 +extern double estimate_num_groups_ext(PlannerInfo *root, List *groupExprs,
 +									  Path *subpath, RelOptInfo *grouped_rel,
 +									  List **pgset);
+ extern double estimate_num_groups(PlannerInfo *root, List *groupExprs,
+ 								  double input_rows, List **pgset);
 
- extern void estimate_hash_bucket_stats(PlannerInfo *root,
- 									   Node *hashkey, double nbuckets,

cardinality_hooks.c

@@ -186,8 +186,7 @@ aqo_get_parameterized_baserel_size(PlannerInfo *root,
 
 		forboth(l, allclauses, l2, selectivities)
 		{
-			current_hash = get_clause_hash(
-										((RestrictInfo *) lfirst(l))->clause,
+			current_hash = get_clause_hash(((AQOClause *) lfirst(l))->clause,
 										   nargs, args_hash, eclass_hash);
 			cache_selectivity(current_hash, rel->relid, rte->relid,
 							  *((double *) lfirst(l2)));

hash.c

@@ -27,6 +27,7 @@
 
 #include "aqo.h"
 #include "hash.h"
+#include "path_utils.h"
 
 static int	get_str_hash(const char *str);
 static int	get_node_hash(Node *node);
@@ -236,11 +237,11 @@ get_fss_for_object(List *relsigns, List *clauselist,
 	i = 0;
 	foreach(lc, clauselist)
 	{
-		RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
+		AQOClause *clause = (AQOClause *) lfirst(lc);
 
-		clause_hashes[i] = get_clause_hash(rinfo->clause,
+		clause_hashes[i] = get_clause_hash(clause->clause,
 										   nargs, args_hash, eclass_hash);
-		args = get_clause_args_ptr(rinfo->clause);
+		args = get_clause_args_ptr(clause->clause);
 		clause_has_consts[i] = (args != NULL && has_consts(*args));
 		i++;
 	}
@@ -335,14 +336,14 @@ get_clause_hash(Expr *clause, int nargs, int *args_hash, int *eclass_hash)
 
 	cclause = copyObject(clause);
 	args = get_clause_args_ptr(cclause);
+	/* XXX: Why does it work even if this loop is removed? */
 	foreach(l, *args)
 	{
 		arg_eclass = get_arg_eclass(get_node_hash(lfirst(l)),
 									nargs, args_hash, eclass_hash);
 		if (arg_eclass != 0)
 		{
-			lfirst(l) = makeNode(Param);
-			((Param *) lfirst(l))->paramid = arg_eclass;
+			lfirst(l) = create_aqo_const_node(AQO_NODE_EXPR, arg_eclass);
 		}
 	}
 	if (!clause_is_eq_clause(clause) || has_consts(*args))
@@ -572,7 +573,7 @@ get_arg_eclass(int arg_hash, int nargs, int *args_hash, int *eclass_hash)
 static void
 get_clauselist_args(List *clauselist, int *nargs, int **args_hash)
 {
-	RestrictInfo *rinfo;
+	AQOClause  *clause;
 	List	  **args;
 	ListCell   *l;
 	ListCell   *l2;
@@ -582,9 +583,9 @@ get_clauselist_args(List *clauselist, int *nargs, int **args_hash)
 
 	foreach(l, clauselist)
 	{
-		rinfo = (RestrictInfo *) lfirst(l);
-		args = get_clause_args_ptr(rinfo->clause);
-		if (args != NULL && clause_is_eq_clause(rinfo->clause))
+		clause = (AQOClause *) lfirst(l);
+		args = get_clause_args_ptr(clause->clause);
+		if (args != NULL && clause_is_eq_clause(clause->clause))
 			foreach(l2, *args)
 				if (!IsA(lfirst(l2), Const))
 				cnt++;
@@ -593,9 +594,9 @@ get_clauselist_args(List *clauselist, int *nargs, int **args_hash)
 	*args_hash = palloc(cnt * sizeof(**args_hash));
 	foreach(l, clauselist)
 	{
-		rinfo = (RestrictInfo *) lfirst(l);
-		args = get_clause_args_ptr(rinfo->clause);
-		if (args != NULL && clause_is_eq_clause(rinfo->clause))
+		clause = (AQOClause *) lfirst(l);
+		args = get_clause_args_ptr(clause->clause);
+		if (args != NULL && clause_is_eq_clause(clause->clause))
 			foreach(l2, *args)
 				if (!IsA(lfirst(l2), Const))
 				(*args_hash)[i++] = get_node_hash(lfirst(l2));
@@ -650,7 +651,7 @@ disjoint_set_merge_eclasses(int *p, int v1, int v2)
 static int *
 perform_eclasses_join(List *clauselist, int nargs, int *args_hash)
 {
-	RestrictInfo *rinfo;
+	AQOClause *clause;
 	int		   *p;
 	ListCell   *l,
 			   *l2;
@@ -664,9 +665,9 @@ perform_eclasses_join(List *clauselist, int nargs, int *args_hash)
 
 	foreach(l, clauselist)
 	{
-		rinfo = (RestrictInfo *) lfirst(l);
-		args = get_clause_args_ptr(rinfo->clause);
-		if (args != NULL && clause_is_eq_clause(rinfo->clause))
+		clause = (AQOClause *) lfirst(l);
+		args = get_clause_args_ptr(clause->clause);
+		if (args != NULL && clause_is_eq_clause(clause->clause))
 		{
 			i3 = -1;
 			foreach(l2, *args)