Change the way static Partition Selector nodes are printed in EXPLAIN

The printablePredicate of a static PartitionSelector node contains Var nodes with varno=INNER. That's bogus, because the PartitionSelector node doesn't actually have any child nodes, but works at execution time because the printablePredicate is not only used by EXPLAIN. In most cases, it still worked, because most Var nodes carry a varnoold field, which is used by EXPLAIN for the lookup, but there was one case of "bogus varno" error even memorized in the expected output of the regression suite. (PostgreSQL 8.3 changed the way EXPLAIN resolves the printable name so that varnoold no longer saves the bacon, and you would get a lot more of those errors) To fix, teach the EXPLAIN of a Sequence node to also reach into the static PartitionSelector node, and print the printablePredicate as if that qual was part of the Sequence node directly. The user-visible effect of this is that the static Partition Selector expression now appears in EXPLAIN output as a direct attribute of the Sequence node, not as a separate child node. Also, if a static Partition Selector doesn't have a "printablePredicate", i.e. it doesn't actually do any selection, it's not printed at all.
jet2007 · Jun 15, 2016 · 5dc7dda · 5dc7dda
1 parent 84286b9
commit 5dc7dda
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Showing 16 changed files with 243 additions and 178 deletions.
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
@@ -103,7 +103,7 @@ show_motion_keys(Plan *plan, List *hashExpr, int nkeys, AttrNumber *keycols,
 			     const char *qlabel,
                  StringInfo str, int indent, ExplainState *es);
 static void
-show_static_part_selection(Plan *plan, int indent, StringInfo str);
+show_static_part_selection(PartitionSelector *ps, Sequence *parent, StringInfo str, int indent, ExplainState *es);
 
 static const char *explain_get_index_name(Oid indexId);
 
@@ -1667,7 +1667,24 @@ explain_outNode(StringInfo str,
 								NULL, outerPlan(plan),
 								NULL, NULL,
 								str, indent, es);
-				show_static_part_selection(plan, indent, str);
+				if (((PartitionSelector *) plan)->staticSelection)
+				{
+					/*
+					 * We should not encounter static selectors as part of the
+					 * normal plan traversal: they are handled specially, as
+					 * part of a Sequence node.
+					 */
+					elog(WARNING, "unexpected static PartitionSelector");
+				}
+			}
+			break;
+		case T_Sequence:
+			{
+				Sequence *s = (Sequence *) plan;
+
+				if (s->static_selector)
+					show_static_part_selection(s->static_selector, s,
+											   str, indent, es);
 			}
 			break;
 		default:
@@ -2291,15 +2308,25 @@ show_motion_keys(Plan *plan, List *hashExpr, int nkeys, AttrNumber *keycols,
 
 /*
  * Show the number of statically selected partitions if available.
+ *
+ * This is similar to show_upper_qual(), but the "printablePredicate" produced
+ * by ORCA is a bit special: INNER Vars refer to the child of the Sequence node
+ * we are part of.
  */
 static void
-show_static_part_selection(Plan *plan, int indent, StringInfo str)
+show_static_part_selection(PartitionSelector *ps, Sequence *parent,
+						   StringInfo str, int indent, ExplainState *es)
 {
-	PartitionSelector *ps = (PartitionSelector *) plan;
+	if (!ps->staticSelection)
+		return;
 
-	if (! ps->staticSelection)
+	if (ps->printablePredicate)
 	{
-		return;
+		show_upper_qual(list_make1(ps->printablePredicate),
+						"Partition Selector",
+						NULL, NULL,
+						NULL, (Plan *) parent,
+						str, indent, es);
 	}
 
 	int nPartsSelected = list_length(ps->staticPartOids);
@@ -2309,7 +2336,7 @@ show_static_part_selection(Plan *plan, int indent, StringInfo str)
 		appendStringInfoString(str, "  ");
 	}
 
-	appendStringInfo(str, "  Partitions selected:  %d (out of %d)\n", nPartsSelected, nPartsTotal);
+	appendStringInfo(str, "  Partitions selected: %d (out of %d)\n", nPartsSelected, nPartsTotal);
 }
 
 /*

diff --git a/src/backend/executor/nodeSequence.c b/src/backend/executor/nodeSequence.c
@@ -38,7 +38,14 @@ ExecInitSequence(Sequence *node, EState *estate, int eflags)
 	Assert(numSubplans >= 1);
 	sequenceState->subplans = (PlanState **)palloc0(numSubplans * sizeof(PlanState *));
 	sequenceState->numSubplans = numSubplans;
-
+
+	/* Initialize static partition selector, if any */
+	if (node->static_selector)
+	{
+		sequenceState->static_selector =
+			(PartitionSelectorState *) ExecInitNode((Plan *) node->static_selector, estate, eflags);
+	}
+
 	/* Initialize subplans */
 	ListCell *lc;
 	int no = 0;
@@ -110,6 +117,16 @@ ExecSequence(SequenceState *node)
 	 */
 	if (node->initState)
 	{
+		/*
+		 * Run the static partition selector first (XXX: Didn't we do this
+		 * at plan time already?)
+		 */
+		if (node->static_selector)
+		{
+			completeSubplan((PlanState *) node->static_selector);
+			CHECK_FOR_INTERRUPTS();
+		}
+
 		for(int no = 0; no < node->numSubplans - 1; no++)
 		{
 			completeSubplan(node->subplans[no]);

diff --git a/src/backend/gpopt/translate/CTranslatorDXLToPlStmt.cpp b/src/backend/gpopt/translate/CTranslatorDXLToPlStmt.cpp
@@ -4174,7 +4174,31 @@ CTranslatorDXLToPlStmt::PplanSequence
 
 		Plan *pplanChild = PplFromDXL(pdxlnChild, &dxltrctxChild, pplan, pdrgpdxltrctxPrevSiblings);
 
-		psequence->subplans = gpdb::PlAppendElement(psequence->subplans, pplanChild);
+		/*
+		 * When the plan comes out from ORCA, a "static" partition
+		 * selection is represented by a subplan that looks like this:
+		 *
+		 * Sequence
+		 *   -> Partition Selector
+		 *   -> Dynamic Table Scan
+		 *
+		 * The Partition Selector node is a bit special though, as it
+		 * modifies the behaviour of its sibling Dynamic Table Scan
+		 * node, and the printablePredicate can contain Vars that
+		 * refer to a child of the Sequence node, rather than
+		 * children of the PartititionSelector node itself. So in the
+		 * Plan tree, we want to put it in the dedicated
+		 * static_selector field, rather than having it as just
+		 * another child node of the Sequence.
+		 */
+		if (IsA(pplanChild, PartitionSelector))
+		{
+			psequence->static_selector = (PartitionSelector *) pplanChild;
+		}
+		else
+		{
+			psequence->subplans = gpdb::PlAppendElement(psequence->subplans, pplanChild);
+		}
 		pplan->nMotionNodes += pplanChild->nMotionNodes;
 	}
 

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
@@ -298,6 +298,7 @@ _copySequence(Sequence *from)
 	Sequence *newnode = makeNode(Sequence);
 	CopyPlanFields((Plan *) from, (Plan *) newnode);
 	COPY_NODE_FIELD(subplans);
+	COPY_NODE_FIELD(static_selector);
 
 	return newnode;
 }

diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
@@ -448,6 +448,7 @@ _outSequence(StringInfo str, Sequence *node)
 	WRITE_NODE_TYPE("SEQUENCE");
 	_outPlanInfo(str, (Plan *)node);
 	WRITE_NODE_FIELD(subplans);
+	WRITE_NODE_FIELD(static_selector);
 }
 
 static void

diff --git a/src/backend/nodes/readfast.c b/src/backend/nodes/readfast.c
@@ -1528,6 +1528,7 @@ _readSequence(void)
 	READ_LOCALS(Sequence);
 	readPlanInfo((Plan *)local_node);
 	READ_NODE_FIELD(subplans);
+	READ_NODE_FIELD(static_selector);
 	READ_DONE();
 }
 

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
@@ -42,6 +42,8 @@ struct FileScanDescData;
 struct MirroredBufferPoolBulkLoadInfo;
 struct SliceTable;
 
+typedef struct PartitionSelectorState PartitionSelectorState;
+
 /* ----------------
  *	  IndexInfo information
  *
@@ -1525,6 +1527,8 @@ typedef struct SequenceState
 	PlanState **subplans;
 	int			numSubplans;
 
+	PartitionSelectorState *static_selector;
+
 	/*
 	 * True if no subplan has been executed.
 	 */

diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
@@ -21,6 +21,8 @@
 #include "nodes/primnodes.h"
 #include "storage/itemptr.h"
 
+typedef struct PartitionSelector PartitionSelector;
+
 typedef struct DirectDispatchInfo
 {
      /**
@@ -378,6 +380,8 @@ typedef struct Sequence
 {
 	Plan plan;
 	List *subplans;
+
+	PartitionSelector *static_selector;
 } Sequence;
 
 /* ----------------

diff --git a/src/test/regress/expected/bfv_index_optimizer.out b/src/test/regress/expected/bfv_index_optimizer.out
@@ -137,8 +137,8 @@ explain SELECT count(*)
 FROM bfv_tab2_facttable1 ft, bfv_tab2_dimdate dt, bfv_tab2_dimtabl1 dt1
 WHERE ft.wk_id = dt.wk_id
 AND ft.id = dt1.id;
-                                                                      QUERY PLAN                                                                       
--------------------------------------------------------------------------------------------------------------------------------------------------------
+                                                                   QUERY PLAN                                                                    
+-------------------------------------------------------------------------------------------------------------------------------------------------
  Aggregate  (cost=0.00..862.16 rows=1 width=8)
    ->  Gather Motion 3:1  (slice3; segments: 3)  (cost=0.00..862.16 rows=1 width=8)
          ->  Aggregate  (cost=0.00..862.16 rows=1 width=8)
@@ -153,15 +153,14 @@ AND ft.id = dt1.id;
                                        ->  Broadcast Motion 3:3  (slice1; segments: 3)  (cost=0.00..431.00 rows=7 width=4)
                                              ->  Table Scan on bfv_tab2_dimtabl1  (cost=0.00..431.00 rows=3 width=4)
                                        ->  Sequence  (cost=0.00..0.16 rows=1 width=2)
-                                             ->  Partition Selector for bfv_tab2_facttable1 (dynamic scan id: 1)  (cost=10.00..100.00 rows=34 width=4)
-                                                   Partitions selected:  20 (out of 20)
+                                             Partitions selected: 20 (out of 20)
                                              ->  Bitmap Table Scan on bfv_tab2_facttable1 (dynamic scan id: 1)  (cost=0.00..0.16 rows=1 width=2)
                                                    Recheck Cond: bfv_tab2_facttable1.id = bfv_tab2_dimtabl1.id
                                                    ->  Bitmap Index Scan on idx_bfv_tab2_facttable1_1_prt_dflt  (cost=0.00..0.00 rows=0 width=0)
                                                          Index Cond: bfv_tab2_facttable1.id = bfv_tab2_dimtabl1.id
  Settings:  optimizer=on
- Optimizer status: PQO version 1.621
-(22 rows)
+ Optimizer status: PQO version 1.633
+(21 rows)
 
 -- start_ignore
 create language plpythonu;

diff --git a/src/test/regress/expected/bfv_partition_optimizer.out b/src/test/regress/expected/bfv_partition_optimizer.out
@@ -1565,9 +1565,6 @@ select * from pp where b=2 and c=2;
 (0 rows)
 
 select count_operator('explain select * from pp where b=2 and c=2;','Partition Selector');
-WARNING:  bogus var: varno=65000 varattno=2 (ruleutils.c:3186)
-CONTEXT:  SQL statement "explain select * from pp where b=2 and c=2;"
-PL/Python function "count_operator"
  count_operator 
 ----------------
               1
@@ -1664,7 +1661,7 @@ select * from ds_4 a1,ds_4 a2 where a1.month_id = a2.month_id and a1.month_id >
 select count_operator('explain select * from ds_4 a1,ds_4 a2 where a1.month_id = a2.month_id and a1.month_id > E''200800'';','Partition Selector');
  count_operator 
 ----------------
-              2
+              1
 (1 row)
 
 -- CLEANUP

diff --git a/src/test/regress/expected/gp_optimizer.out b/src/test/regress/expected/gp_optimizer.out
@@ -8137,17 +8137,15 @@ select * from orca.t order by 1,2;
 explain select * from orca.t order by 1,2;
                                              QUERY PLAN                                              
 -----------------------------------------------------------------------------------------------------
- Gather Motion 2:1  (slice1; segments: 2)  (cost=0.00..431.00 rows=1 width=32)
+ Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..431.00 rows=1 width=32)
    Merge Key: timest, user_id
    ->  Sequence  (cost=0.00..431.00 rows=1 width=32)
-         ->  Partition Selector for t (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  6 (out of 6)
          ->  Sort  (cost=0.00..431.00 rows=1 width=32)
                Sort Key: timest, user_id
                ->  Dynamic Table Scan on t (dynamic scan id: 1)  (cost=0.00..431.00 rows=1 width=32)
  Settings:  optimizer=on; optimizer_segments=3
- Optimizer status: PQO version 1.630
-(10 rows)
+ Optimizer status: PQO version 1.633
+(8 rows)
 
 select tag2, tag1 from orca.t order by 1, 2;;
  tag2  | tag1  
@@ -8226,19 +8224,17 @@ set optimizer_plan_id = 2;
 explain select * from orca.t_date where user_id=9;
                                                    QUERY PLAN                                                   
 ----------------------------------------------------------------------------------------------------------------
- Gather Motion 2:1  (slice1; segments: 2)  (cost=0.00..437.00 rows=1 width=28)
+ Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..437.00 rows=1 width=28)
    ->  Sequence  (cost=0.00..437.00 rows=1 width=28)
-         ->  Partition Selector for t_date (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  6 (out of 6)
          ->  Result  (cost=0.00..437.00 rows=1 width=28)
                ->  Append  (cost=0.00..437.00 rows=1 width=28)
                      ->  Dynamic Index Scan on t_date (dynamic scan id: 1)  (cost=0.00..6.00 rows=1 width=58)
                            Index Cond: user_id = 9::numeric
                      ->  Dynamic Table Scan on t_date (dynamic scan id: 1)  (cost=0.00..431.00 rows=1 width=58)
                            Filter: user_id = 9::numeric
  Settings:  optimizer=on; optimizer_segments=3
- Optimizer status: PQO version 1.602
-(12 rows)
+ Optimizer status: PQO version 1.633
+(10 rows)
 
 select * from orca.t_date where user_id=9;
    timest   | user_id | tag1  | tag2  
@@ -8281,19 +8277,17 @@ set optimizer_plan_id = 2;
 explain select * from orca.t_text where user_id=9;
                                                    QUERY PLAN                                                   
 ----------------------------------------------------------------------------------------------------------------
- Gather Motion 2:1  (slice1; segments: 2)  (cost=0.00..437.00 rows=1 width=28)
+ Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..437.00 rows=1 width=28)
    ->  Sequence  (cost=0.00..437.00 rows=1 width=28)
-         ->  Partition Selector for t_text (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  3 (out of 3)
          ->  Result  (cost=0.00..437.00 rows=1 width=28)
                ->  Append  (cost=0.00..437.00 rows=1 width=28)
                      ->  Dynamic Index Scan on t_text (dynamic scan id: 1)  (cost=0.00..6.00 rows=1 width=58)
                            Index Cond: user_id = 9::numeric
                      ->  Dynamic Table Scan on t_text (dynamic scan id: 1)  (cost=0.00..431.00 rows=1 width=58)
                            Filter: user_id = 9::numeric
  Settings:  optimizer=on; optimizer_segments=3
- Optimizer status: PQO version 1.602
-(12 rows)
+ Optimizer status: PQO version 1.633
+(10 rows)
 
 select * from orca.t_text where user_id=9;
    timest   | user_id | tag1  | tag2  
@@ -8348,17 +8342,15 @@ select disable_xform('CXformDynamicGet2DynamicTableScan');
 (1 row)
 
 explain select * from orca.t_employee where user_id = 2;
-                                                QUERY PLAN                                                
-----------------------------------------------------------------------------------------------------------
+                                              QUERY PLAN                                              
+------------------------------------------------------------------------------------------------------
  Gather Motion 1:1  (slice1; segments: 1)  (cost=0.00..6.00 rows=1 width=28)
    ->  Sequence  (cost=0.00..6.00 rows=1 width=28)
-         ->  Partition Selector for t_employee (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  2 (out of 2)
          ->  Dynamic Index Scan on t_employee (dynamic scan id: 1)  (cost=0.00..6.00 rows=1 width=28)
                Index Cond: user_id = 2::numeric
  Settings:  optimizer=on; optimizer_segments=3
- Optimizer status: PQO version 1.602
-(8 rows)
+ Optimizer status: PQO version 1.633
+(6 rows)
 
 select * from orca.t_employee where user_id = 2;
    timest   | user_id | tag1  |     emp      
@@ -8401,19 +8393,17 @@ set optimizer_plan_id = 2;
 explain select * from orca.t_ceeval_ints where user_id=4;
                                                       QUERY PLAN                                                       
 -----------------------------------------------------------------------------------------------------------------------
- Gather Motion 2:1  (slice1; segments: 2)  (cost=0.00..437.00 rows=1 width=28)
+ Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..437.00 rows=1 width=28)
    ->  Sequence  (cost=0.00..437.00 rows=1 width=28)
-         ->  Partition Selector for t_ceeval_ints (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  3 (out of 3)
          ->  Result  (cost=0.00..437.00 rows=1 width=28)
                ->  Append  (cost=0.00..437.00 rows=1 width=28)
                      ->  Dynamic Index Scan on t_ceeval_ints (dynamic scan id: 1)  (cost=0.00..6.00 rows=1 width=58)
                            Index Cond: user_id = 4::numeric
                      ->  Dynamic Table Scan on t_ceeval_ints (dynamic scan id: 1)  (cost=0.00..431.00 rows=1 width=58)
                            Filter: user_id = 4::numeric
  Settings:  optimizer=on; optimizer_segments=3
- Optimizer status: PQO version 1.602
-(12 rows)
+ Optimizer status: PQO version 1.633
+(10 rows)
 
 select * from orca.t_ceeval_ints where user_id=4;
  user_id | category_id | tag1  | tag2  
@@ -9213,20 +9203,18 @@ insert into orca.bm_dyn_test values(2, 5, '2');
 set optimizer_enable_bitmapscan=on;
 -- gather on 1 segment because of direct dispatch
 explain select * from orca.bm_dyn_test where i=2 and t='2';
-                                                QUERY PLAN                                                 
------------------------------------------------------------------------------------------------------------
+                                              QUERY PLAN                                              
+------------------------------------------------------------------------------------------------------
  Gather Motion 1:1  (slice1; segments: 1)  (cost=0.00..0.00 rows=1 width=16)
    ->  Sequence  (cost=0.00..0.00 rows=1 width=16)
-         ->  Partition Selector for bm_dyn_test (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-               Partitions selected:  6 (out of 6)
          ->  Bitmap Table Scan on bm_dyn_test (dynamic scan id: 1)  (cost=0.00..0.00 rows=1 width=16)
                Recheck Cond: i = 2
                Filter: i = 2 AND t = '2'::text
                ->  Bitmap Index Scan on bm_dyn_test_idx_1_prt_part0  (cost=0.00..0.00 rows=0 width=0)
                      Index Cond: i = 2
  Settings:  optimizer=on
- Optimizer status: PQO version 1.602
-(11 rows)
+ Optimizer status: PQO version 1.633
+(9 rows)
 
 select * from orca.bm_dyn_test where i=2 and t='2';
  i | j | t 
@@ -9750,8 +9738,6 @@ ORDER BY 1 asc ;
                                              ->  Materialize  (cost=0.00..431.00 rows=1 width=1)
                                                    ->  Table Scan on my_tt_agg_opt  (cost=0.00..431.00 rows=1 width=62)
                                        ->  Sequence  (cost=0.00..874.01 rows=1 width=8)
-                                             ->  Partition Selector for my_tq_agg_opt_part (dynamic scan id: 1)  (cost=10.00..100.00 rows=50 width=4)
-                                                   Partitions selected:  2 (out of 2)
                                              ->  Result  (cost=0.00..874.01 rows=1 width=8)
                                                    ->  Append  (cost=0.00..874.01 rows=1 width=8)
                                                          ->  Nested Loop  (cost=0.00..437.00 rows=1 width=132)