planner: Manual revert of pingcap#24282 (pingcap#35298)

ref pingcap#22079, closes pingcap#33966, close pingcap#35181

Author: mjonss

executor/partition_table_test.go

@@ -3600,3 +3600,18 @@ func TestPartitionTableExplain(t *testing.T) {
 		"  └─Selection 1.00 cop[tikv]  not(isnull(testpartitiontableexplain.t.b))",
 		"    └─TableRangeScan 1.00 cop[tikv] table:t range:[1,1], keep order:false"))
 }
+
+func TestIssue35181(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("create database TestIssue35181")
+	tk.MustExec("use TestIssue35181")
+	tk.MustExec("CREATE TABLE `t` (`a` int(11) DEFAULT NULL, `b` int(11) DEFAULT NULL) PARTITION BY RANGE (`a`) (PARTITION `p0` VALUES LESS THAN (2021), PARTITION `p1` VALUES LESS THAN (3000))")
+
+	tk.MustExec("set @@tidb_partition_prune_mode = 'static'")
+	tk.MustExec(`insert into t select * from t where a=3000`)
+	tk.MustExec("set @@tidb_partition_prune_mode = 'dynamic'")
+	tk.MustExec(`insert into t select * from t where a=3000`)
+}

planner/core/partition_prune.go

@@ -33,7 +33,7 @@ func PartitionPruning(ctx sessionctx.Context, tbl table.PartitionedTable, conds
 	case model.PartitionTypeHash:
 		return s.pruneHashPartition(ctx, tbl, partitionNames, conds, columns, names)
 	case model.PartitionTypeRange:
-		rangeOr, _, err := s.pruneRangePartition(ctx, pi, tbl, conds, columns, names, nil)
+		rangeOr, err := s.pruneRangePartition(ctx, pi, tbl, conds, columns, names)
 		if err != nil {
 			return nil, err
 		}

planner/core/rule_partition_processor.go

@@ -825,26 +825,26 @@ func intersectionRange(start, end, newStart, newEnd int) (int, int) {
 }
 
 func (s *partitionProcessor) pruneRangePartition(ctx sessionctx.Context, pi *model.PartitionInfo, tbl table.PartitionedTable, conds []expression.Expression,
-	columns []*expression.Column, names types.NameSlice, condsToBePruned *[]expression.Expression) (partitionRangeOR, []expression.Expression, error) {
+	columns []*expression.Column, names types.NameSlice) (partitionRangeOR, error) {
 	partExpr, err := tbl.(partitionTable).PartitionExpr()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	// Partition by range columns.
 	if len(pi.Columns) > 0 {
 		result, err := s.pruneRangeColumnsPartition(ctx, conds, pi, partExpr, columns, names)
-		return result, nil, err
+		return result, err
 	}
 
 	// Partition by range.
 	col, fn, mono, err := makePartitionByFnCol(ctx, columns, names, pi.Expr)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	result := fullRange(len(pi.Definitions))
 	if col == nil {
-		return result, nil, nil
+		return result, nil
 	}
 
 	// Extract the partition column, if the column is not null, it's possible to prune.
@@ -859,41 +859,14 @@ func (s *partitionProcessor) pruneRangePartition(ctx sessionctx.Context, pi *mod
 	}
 	result = partitionRangeForCNFExpr(ctx, conds, &pruner, result)
 
-	if condsToBePruned == nil {
-		return result, nil, nil
-	}
-	// remove useless predicates after pruning
-	newConds := make([]expression.Expression, 0, len(*condsToBePruned))
-	for _, cond := range *condsToBePruned {
-		if dataForPrune, ok := pruner.extractDataForPrune(ctx, cond); ok {
-			switch dataForPrune.op {
-			case ast.EQ:
-				unsigned := mysql.HasUnsignedFlag(pruner.col.RetType.GetFlag())
-				start, _ := pruneUseBinarySearch(pruner.lessThan, dataForPrune, unsigned)
-				// if the type of partition key is Int
-				if pk, ok := partExpr.Expr.(*expression.Column); ok && pk.RetType.EvalType() == types.ETInt {
-					// see if can be removed
-					// see issue #22079: https://github.com/pingcap/tidb/issues/22079 for details
-					if start > 0 && pruner.lessThan.data[start-1] == dataForPrune.c && (pruner.lessThan.data[start]-1) == dataForPrune.c {
-						continue
-					}
-				}
-			}
-		}
-		newConds = append(newConds, cond)
-	}
-
-	return result, newConds, nil
+	return result, nil
 }
 
 func (s *partitionProcessor) processRangePartition(ds *DataSource, pi *model.PartitionInfo, opt *logicalOptimizeOp) (LogicalPlan, error) {
-	used, prunedConds, err := s.pruneRangePartition(ds.ctx, pi, ds.table.(table.PartitionedTable), ds.allConds, ds.TblCols, ds.names, &ds.pushedDownConds)
+	used, err := s.pruneRangePartition(ds.ctx, pi, ds.table.(table.PartitionedTable), ds.allConds, ds.TblCols, ds.names)
 	if err != nil {
 		return nil, err
 	}
-	if prunedConds != nil {
-		ds.pushedDownConds = prunedConds
-	}
 	return s.makeUnionAllChildren(ds, pi, used, opt)
 }
 
@@ -1280,11 +1253,13 @@ func relaxOP(op string) string {
 	return op
 }
 
+// pruneUseBinarySearch returns the start and end of which partitions will match.
+// If no match (i.e. value > last partition) the start partition will be the number of partition, not the first partition!
 func pruneUseBinarySearch(lessThan lessThanDataInt, data dataForPrune, unsigned bool) (start int, end int) {
 	length := lessThan.length()
 	switch data.op {
 	case ast.EQ:
-		// col = 66, lessThan = [4 7 11 14 17] => [5, 6)
+		// col = 66, lessThan = [4 7 11 14 17] => [5, 5)
 		// col = 14, lessThan = [4 7 11 14 17] => [4, 5)
 		// col = 10, lessThan = [4 7 11 14 17] => [2, 3)
 		// col = 3, lessThan = [4 7 11 14 17] => [0, 1)
@@ -1590,6 +1565,8 @@ func (p *rangeColumnsPruner) partitionRangeForExpr(sctx sessionctx.Context, expr
 	return start, end, true
 }
 
+// pruneUseBinarySearch returns the start and end of which partitions will match.
+// If no match (i.e. value > last partition) the start partition will be the number of partition, not the first partition!
 func (p *rangeColumnsPruner) pruneUseBinarySearch(sctx sessionctx.Context, op string, data *expression.Constant) (start int, end int) {
 	var err error
 	var isNull bool

planner/core/testdata/partition_pruner_out.json

@@ -2843,15 +2843,17 @@
       {
         "SQL": "explain format = 'brief' select * from t where a = 1",
         "Result": [
-          "TableReader 10000.00 root  data:TableFullScan",
-          "└─TableFullScan 10000.00 cop[tikv] table:t, partition:p1 keep order:false, stats:pseudo"
+          "TableReader 10.00 root  data:Selection",
+          "└─Selection 10.00 cop[tikv]  eq(test_partition.t.a, 1)",
+          "  └─TableFullScan 10000.00 cop[tikv] table:t, partition:p1 keep order:false, stats:pseudo"
         ]
       },
       {
         "SQL": "explain format = 'brief' select * from t where a = 2",
         "Result": [
-          "TableReader 10000.00 root  data:TableFullScan",
-          "└─TableFullScan 10000.00 cop[tikv] table:t, partition:p2 keep order:false, stats:pseudo"
+          "TableReader 10.00 root  data:Selection",
+          "└─Selection 10.00 cop[tikv]  eq(test_partition.t.a, 2)",
+          "  └─TableFullScan 10000.00 cop[tikv] table:t, partition:p2 keep order:false, stats:pseudo"
         ]
       },
       {
@@ -2899,8 +2901,9 @@
       {
         "SQL": "explain format = 'brief' select * from t where a in (2)",
         "Result": [
-          "TableReader 10000.00 root  data:TableFullScan",
-          "└─TableFullScan 10000.00 cop[tikv] table:t, partition:p2 keep order:false, stats:pseudo"
+          "TableReader 10.00 root  data:Selection",
+          "└─Selection 10.00 cop[tikv]  eq(test_partition.t.a, 2)",
+          "  └─TableFullScan 10000.00 cop[tikv] table:t, partition:p2 keep order:false, stats:pseudo"
         ]
       }
     ]