refine code

Signed-off-by: guo-shaoge <shaoge1994@163.com>
pingcap · Apr 16, 2021 · b6cd2e5 · b6cd2e5
1 parent dcea842
commit b6cd2e5
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Showing 4 changed files with 61 additions and 60 deletions.
diff --git a/cmd/explaintest/r/explain_easy.result b/cmd/explaintest/r/explain_easy.result
@@ -194,29 +194,29 @@ test	t4	1	expr_idx	1	NULL	NULL		(`a` + `b` + 1)	2	YES	NO
 explain format = 'brief' select count(1) from (select count(1) from (select * from t1 where c3 = 100) k) k2;
 id	estRows	task	access object	operator info
 StreamAgg	1.00	root		funcs:count(1)->Column#5
-└─StreamAgg	1.00	root		funcs:firstrow(Column#11)->Column#9
+└─StreamAgg	1.00	root		funcs:firstrow(Column#13)->Column#11
   └─TableReader	1.00	root		data:StreamAgg
-    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#11
+    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#13
       └─Selection	10.00	cop[tikv]		eq(test.t1.c3, 100)
         └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
 explain format = 'brief' select 1 from (select count(c2), count(c3) from t1) k;
 id	estRows	task	access object	operator info
 Projection	1.00	root		1->Column#6
-└─StreamAgg	1.00	root		funcs:firstrow(Column#15)->Column#10
+└─StreamAgg	1.00	root		funcs:firstrow(Column#16)->Column#11
   └─TableReader	1.00	root		data:StreamAgg
-    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#15
+    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#16
       └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
 explain format = 'brief' select count(1) from (select max(c2), count(c3) as m from t1) k;
 id	estRows	task	access object	operator info
 StreamAgg	1.00	root		funcs:count(1)->Column#6
-└─StreamAgg	1.00	root		funcs:firstrow(Column#14)->Column#9
+└─StreamAgg	1.00	root		funcs:firstrow(Column#15)->Column#10
   └─TableReader	1.00	root		data:StreamAgg
-    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#14
+    └─StreamAgg	1.00	cop[tikv]		funcs:firstrow(1)->Column#15
       └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
 explain format = 'brief' select count(1) from (select count(c2) from t1 group by c3) k;
 id	estRows	task	access object	operator info
 StreamAgg	1.00	root		funcs:count(1)->Column#5
-└─HashAgg	8000.00	root		group by:test.t1.c3, funcs:firstrow(1)->Column#8
+└─HashAgg	8000.00	root		group by:test.t1.c3, funcs:firstrow(1)->Column#9
   └─TableReader	10000.00	root		data:TableFullScan
     └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
 set @@session.tidb_opt_insubq_to_join_and_agg=0;
@@ -498,8 +498,8 @@ PRIMARY KEY (`id`)
 explain format = 'brief' SELECT COUNT(1) FROM (SELECT COALESCE(b.region_name, '不详') region_name, SUM(a.registration_num) registration_num FROM (SELECT stat_date, show_date, region_id, 0 registration_num FROM test01 WHERE period = 1 AND stat_date >= 20191202 AND stat_date <= 20191202 UNION ALL SELECT stat_date, show_date, region_id, registration_num registration_num FROM test01 WHERE period = 1 AND stat_date >= 20191202 AND stat_date <= 20191202) a LEFT JOIN test02 b ON a.region_id = b.id WHERE registration_num > 0 AND a.stat_date >= '20191202' AND a.stat_date <= '20191202' GROUP BY a.stat_date , a.show_date , COALESCE(b.region_name, '不详') ) JLS;
 id	estRows	task	access object	operator info
 StreamAgg	1.00	root		funcs:count(1)->Column#22
-└─HashAgg	8000.00	root		group by:Column#33, Column#34, Column#35, funcs:firstrow(1)->Column#32
-  └─Projection	10000.01	root		Column#14, Column#15, coalesce(test.test02.region_name, 不详)->Column#35
+└─HashAgg	8000.00	root		group by:Column#34, Column#35, Column#36, funcs:firstrow(1)->Column#33
+  └─Projection	10000.01	root		Column#14, Column#15, coalesce(test.test02.region_name, 不详)->Column#36
     └─HashJoin	10000.01	root		left outer join, equal:[eq(Column#16, test.test02.id)]
       ├─TableReader(Build)	10000.00	root		data:TableFullScan
       │ └─TableFullScan	10000.00	cop[tikv]	table:b	keep order:false, stats:pseudo

diff --git a/cmd/explaintest/r/explain_join_stats.result b/cmd/explaintest/r/explain_join_stats.result
@@ -7,7 +7,7 @@ load stats 's/explain_join_stats_lo.json';
 explain format = 'brief' select count(*) from e, lo where lo.a=e.a and e.b=22336;
 id	estRows	task	access object	operator info
 StreamAgg	1.00	root		funcs:count(1)->Column#5
-└─Projection	19977.00	root		1->Column#0
+└─Projection	19977.00	root		1->Column#6
   └─HashJoin	19977.00	root		inner join, equal:[eq(test.lo.a, test.e.a)]
     ├─TableReader(Build)	250.00	root		data:TableFullScan
     │ └─TableFullScan	250.00	cop[tikv]	table:lo	keep order:false

diff --git a/planner/core/rule_column_pruning.go b/planner/core/rule_column_pruning.go
@@ -22,7 +22,6 @@ import (
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/expression/aggregation"
 	"github.com/pingcap/tidb/planner/util"
-	"github.com/pingcap/tidb/types"
 )
 
 type columnPruner struct {
@@ -74,12 +73,14 @@ func (p *LogicalProjection) PruneColumns(parentUsedCols []*expression.Column) er
 	}
 	// Here we add a constant 1 to avoid Projection operator is eliminated.(#23887)
 	if len(p.Exprs) == 0 {
+		constOne := expression.NewOne()
 		p.schema.Append(&expression.Column{
-			RetType: types.NewFieldType(mysql.TypeLong),
+			UniqueID: p.ctx.GetSessionVars().AllocPlanColumnID(),
+			RetType:  constOne.GetType(),
 		})
 		p.Exprs = append(p.Exprs, &expression.Constant{
-			Value:   types.NewDatum(1),
-			RetType: types.NewFieldType(mysql.TypeLong),
+			Value:   constOne.Value,
+			RetType: constOne.GetType(),
 		})
 	}
 	selfUsedCols := make([]*expression.Column, 0, len(p.Exprs))