show pruning clause of Runtime[Merge]Append

Author: funbringer

expected/pathman_join_clause.out

@@ -40,6 +40,7 @@ SELECT m.tableoid::regclass, id1, id2, key, start_key, end_key
  Nested Loop
    ->  Seq Scan on fk
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (fk.id1 = m.id1)
          ->  Bitmap Heap Scan on mytbl_0 m
                Recheck Cond: (id1 = fk.id1)
                Filter: ((fk.id2 = id2) AND (NOT (key <@ int4range(6, fk.end_key))))
@@ -80,7 +81,7 @@ SELECT m.tableoid::regclass, id1, id2, key, start_key, end_key
                Filter: ((fk.id2 = id2) AND (NOT (key <@ int4range(6, fk.end_key))))
                ->  Bitmap Index Scan on mytbl_7_pkey
                      Index Cond: (id1 = fk.id1)
-(43 rows)
+(44 rows)
 
 /* test joint data */
 SELECT m.tableoid::regclass, id1, id2, key, start_key, end_key

expected/pathman_only.out

@@ -178,6 +178,7 @@ SELECT * FROM test_only.from_only_test JOIN q1 USING(val);
      ->  Seq Scan on from_only_test from_only_test_1
    ->  CTE Scan on q1
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (q1.val = from_only_test.val)
          ->  Seq Scan on from_only_test_1 from_only_test
                Filter: (q1.val = val)
          ->  Seq Scan on from_only_test_2 from_only_test
@@ -198,7 +199,7 @@ SELECT * FROM test_only.from_only_test JOIN q1 USING(val);
                Filter: (q1.val = val)
          ->  Seq Scan on from_only_test_10 from_only_test
                Filter: (q1.val = val)
-(25 rows)
+(26 rows)
 
 /* should be OK */
 EXPLAIN (COSTS OFF)
@@ -209,6 +210,7 @@ WHERE val = (SELECT val FROM ONLY test_only.from_only_test
                            QUERY PLAN                            
 -----------------------------------------------------------------
  Custom Scan (RuntimeAppend)
+   Prune by: (from_only_test.val = $0)
    InitPlan 1 (returns $0)
      ->  Limit
            ->  Sort
@@ -234,7 +236,7 @@ WHERE val = (SELECT val FROM ONLY test_only.from_only_test
          Filter: (val = $0)
    ->  Seq Scan on from_only_test_10 from_only_test
          Filter: (val = $0)
-(26 rows)
+(27 rows)
 
 DROP SCHEMA test_only CASCADE;
 NOTICE:  drop cascades to 12 other objects

expected/pathman_rowmarks.out

@@ -100,6 +100,7 @@ FOR SHARE;
                              ->  Seq Scan on first_3
                              ->  Seq Scan on first_4
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (first.id = $1)
          ->  Seq Scan on first_0 first
                Filter: (id = $1)
          ->  Seq Scan on first_1 first
@@ -110,7 +111,7 @@ FOR SHARE;
                Filter: (id = $1)
          ->  Seq Scan on first_4 first
                Filter: (id = $1)
-(23 rows)
+(24 rows)
 
 /* A little harder (execution) */
 SELECT * FROM rowmarks.first
@@ -142,6 +143,7 @@ FOR SHARE;
                        Sort Key: second.id
                        ->  Seq Scan on second
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (first.id = $1)
          ->  Seq Scan on first_0 first
                Filter: (id = $1)
          ->  Seq Scan on first_1 first
@@ -152,7 +154,7 @@ FOR SHARE;
                Filter: (id = $1)
          ->  Seq Scan on first_4 first
                Filter: (id = $1)
-(18 rows)
+(19 rows)
 
 /* Two tables (execution) */
 SELECT * FROM rowmarks.first

expected/pathman_runtime_nodes.out

@@ -318,6 +318,7 @@ join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;
    ->  Limit
          ->  Seq Scan on run_values
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (run_values.val = t1.id)
          ->  Seq Scan on runtime_test_1 t1
                Filter: (run_values.val = id)
          ->  Index Only Scan using runtime_test_1_0_pkey on runtime_test_1_0 t1
@@ -332,7 +333,7 @@ join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;
                Index Cond: (id = run_values.val)
          ->  Index Only Scan using runtime_test_1_5_pkey on runtime_test_1_5 t1
                Index Cond: (id = run_values.val)
-(18 rows)
+(19 rows)
 
 select from test.runtime_test_1 as t1
 join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;
@@ -355,6 +356,7 @@ join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;
    ->  Limit
          ->  Seq Scan on run_values
    ->  Custom Scan (RuntimeAppend)
+         Prune by: (run_values.val = t1.id)
          ->  Index Only Scan using runtime_test_1_0_pkey on runtime_test_1_0 t1
                Index Cond: (id = run_values.val)
          ->  Index Only Scan using runtime_test_1_1_pkey on runtime_test_1_1 t1
@@ -367,7 +369,7 @@ join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;
                Index Cond: (id = run_values.val)
          ->  Index Only Scan using runtime_test_1_5_pkey on runtime_test_1_5 t1
                Index Cond: (id = run_values.val)
-(16 rows)
+(17 rows)
 
 select from test.runtime_test_1 as t1
 join (select * from test.run_values limit 4) as t2 on t1.id = t2.val;

src/include/nodes_common.h

@@ -98,8 +98,10 @@ void end_append_common(CustomScanState *node);
 void rescan_append_common(CustomScanState *node);
 
 void explain_append_common(CustomScanState *node,
+						   List *ancestors,
+						   ExplainState *es,
 						   HTAB *children_table,
-						   ExplainState *es);
+						   List *custom_exprs);
 
 
 #endif /* NODES_COMMON_H */

src/nodes_common.c

@@ -13,11 +13,13 @@
 #include "utils.h"
 
 #include "access/sysattr.h"
+#include "optimizer/clauses.h"
 #include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
 #include "optimizer/var.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/memutils.h"
+#include "utils/ruleutils.h"
 
 
 /* Allocation settings */
@@ -688,8 +690,27 @@ rescan_append_common(CustomScanState *node)
 }
 
 void
-explain_append_common(CustomScanState *node, HTAB *children_table, ExplainState *es)
+explain_append_common(CustomScanState *node,
+					  List *ancestors,
+					  ExplainState *es,
+					  HTAB *children_table,
+					  List *custom_exprs)
 {
+	List *deparse_context;
+	char *exprstr;
+
+	/* Set up deparsing context */
+	deparse_context = set_deparse_context_planstate(es->deparse_cxt,
+													(Node *) node,
+													ancestors);
+
+	/* Deparse the expression */
+	exprstr = deparse_expression((Node *) make_ands_explicit(custom_exprs),
+								 deparse_context, true, false);
+
+	/* And add to es->str */
+	ExplainPropertyText("Prune by", exprstr, es);
+
 	/* Construct excess PlanStates */
 	if (!es->analyze)
 	{

src/runtime_merge_append.c

@@ -482,7 +482,9 @@ runtimemergeappend_explain(CustomScanState *node, List *ancestors, ExplainState
 {
 	RuntimeMergeAppendState *scan_state = (RuntimeMergeAppendState *) node;
 
-	explain_append_common(node, scan_state->rstate.children_table, es);
+	explain_append_common(node, ancestors, es,
+						  scan_state->rstate.children_table,
+						  scan_state->rstate.custom_exprs);
 
 	/* We should print sort keys as well */
 	show_sort_group_keys((PlanState *) &node->ss.ps, "Sort Key",

src/runtimeappend.c

@@ -140,5 +140,7 @@ runtimeappend_explain(CustomScanState *node, List *ancestors, ExplainState *es)
 {
 	RuntimeAppendState *scan_state = (RuntimeAppendState *) node;
 
-	explain_append_common(node, scan_state->children_table, es);
+	explain_append_common(node, ancestors, es,
+						  scan_state->children_table,
+						  scan_state->custom_exprs);
 }