table: Add option DupKeyCheckLazy to check duplicated key lazily

pkg/executor/builder.go

@@ -999,6 +999,7 @@ func (b *executorBuilder) buildInsert(v *plannercore.Insert) exec.Executor {
 	insert := &InsertExec{
 		InsertValues: ivs,
 		OnDuplicate:  append(v.OnDuplicate, v.GenCols.OnDuplicates...),
+		IgnoreErr:    v.IgnoreErr,
 	}
 	return insert
 }
@@ -2650,6 +2651,7 @@ func (b *executorBuilder) buildUpdate(v *plannercore.Update) exec.Executor {
 		tblID2table:               tblID2table,
 		tblColPosInfos:            v.TblColPosInfos,
 		assignFlag:                assignFlag,
+		IgnoreError:               v.IgnoreError,
 	}
 	updateExec.fkChecks, b.err = buildTblID2FKCheckExecs(b.ctx, tblID2table, v.FKChecks)
 	if b.err != nil {

pkg/executor/insert.go

@@ -22,7 +22,6 @@ import (
 	"time"
 
 	"github.com/pingcap/errors"
-	"github.com/pingcap/tidb/pkg/errctx"
 	"github.com/pingcap/tidb/pkg/errno"
 	"github.com/pingcap/tidb/pkg/executor/internal/exec"
 	"github.com/pingcap/tidb/pkg/expression"
@@ -31,6 +30,7 @@ import (
 	"github.com/pingcap/tidb/pkg/parser/model"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
 	"github.com/pingcap/tidb/pkg/parser/terror"
+	"github.com/pingcap/tidb/pkg/sessionctx/variable"
 	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/table/tables"
 	"github.com/pingcap/tidb/pkg/tablecodec"
@@ -47,6 +47,7 @@ import (
 type InsertExec struct {
 	*InsertValues
 	OnDuplicate    []*expression.Assignment
+	IgnoreErr      bool
 	evalBuffer4Dup chunk.MutRow
 	curInsertVals  chunk.MutRow
 	row4Update     []types.Datum
@@ -66,7 +67,6 @@ func (e *InsertExec) exec(ctx context.Context, rows [][]types.Datum) error {
 	// If tidb_batch_insert is ON and not in a transaction, we could use BatchInsert mode.
 	sessVars := e.Ctx().GetSessionVars()
 	defer sessVars.CleanBuffers()
-	ignoreErr := sessVars.StmtCtx.ErrGroupLevel(errctx.ErrGroupDupKey) != errctx.LevelError
 
 	txn, err := e.Ctx().Txn(true)
 	if err != nil {
@@ -92,13 +92,14 @@ func (e *InsertExec) exec(ctx context.Context, rows [][]types.Datum) error {
 		if err != nil {
 			return err
 		}
-	} else if ignoreErr {
+	} else if e.IgnoreErr {
 		err := e.batchCheckAndInsert(ctx, rows, e.addRecord, false)
 		if err != nil {
 			return err
 		}
 	} else {
 		start := time.Now()
+		dupKeyCheck := optimizeDupKeyCheckForNormalInsert(sessVars, txn)
 		for i, row := range rows {
 			var err error
 			sizeHintStep := int(sessVars.ShardAllocateStep)
@@ -108,9 +109,9 @@ func (e *InsertExec) exec(ctx context.Context, rows [][]types.Datum) error {
 				if sizeHint > remain {
 					sizeHint = remain
 				}
-				err = e.addRecordWithAutoIDHint(ctx, row, sizeHint, table.DupKeyCheckDefault)
+				err = e.addRecordWithAutoIDHint(ctx, row, sizeHint, dupKeyCheck)
 			} else {
-				err = e.addRecord(ctx, row, table.DupKeyCheckDefault)
+				err = e.addRecord(ctx, row, dupKeyCheck)
 			}
 			if err != nil {
 				return err
@@ -193,7 +194,7 @@ func (e *InsertValues) prefetchDataCache(ctx context.Context, txn kv.Transaction
 }
 
 // updateDupRow updates a duplicate row to a new row.
-func (e *InsertExec) updateDupRow(ctx context.Context, idxInBatch int, txn kv.Transaction, row toBeCheckedRow, handle kv.Handle, _ []*expression.Assignment) error {
+func (e *InsertExec) updateDupRow(ctx context.Context, idxInBatch int, txn kv.Transaction, row toBeCheckedRow, handle kv.Handle, _ []*expression.Assignment, dupKeyCheck table.DupKeyCheckMode) error {
 	oldRow, err := getOldRow(ctx, e.Ctx(), txn, row.t, handle, e.GenExprs)
 	if err != nil {
 		return err
@@ -204,7 +205,7 @@ func (e *InsertExec) updateDupRow(ctx context.Context, idxInBatch int, txn kv.Tr
 		extraCols = e.Ctx().GetSessionVars().CurrInsertBatchExtraCols[idxInBatch]
 	}
 
-	err = e.doDupRowUpdate(ctx, handle, oldRow, row.row, extraCols, e.OnDuplicate, idxInBatch)
+	err = e.doDupRowUpdate(ctx, handle, oldRow, row.row, extraCols, e.OnDuplicate, idxInBatch, dupKeyCheck)
 	if kv.ErrKeyExists.Equal(err) || table.ErrCheckConstraintViolated.Equal(err) {
 		ec := e.Ctx().GetSessionVars().StmtCtx.ErrCtx()
 		return ec.HandleErrorWithAlias(kv.ErrKeyExists, err, err)
@@ -236,14 +237,29 @@ func (e *InsertExec) batchUpdateDupRows(ctx context.Context, newRows [][]types.D
 		e.stats.Prefetch += time.Since(prefetchStart)
 	}
 
+	// If the current row has some conflicts, the operation will be changed to update.
+	// If this happens, there still may be another index that has a conflict,
+	// so we need to determine DupKeyCheckMode here.
+	var dupKeyCheck table.DupKeyCheckMode
+	if e.IgnoreErr || !txn.IsPipelined() {
+		// If the current statement is `INSERT IGNORE ... ON DUPLICATE KEY ...`, `DupKeyCheckInPlace` should be used.
+		// It is because the executor should get the dup-key error immediately and ignore it.
+		// However, if `txn.IsPipeline()` returns true, we need force to use `DupKeyCheckLazy` to save performance,
+		// even if it may cause the dup-key error cannot be handled in time and returned to the user.
+		// See comment in issue: https://github.com/pingcap/tidb/issues/55187#issuecomment-2268356459
+		dupKeyCheck = table.DupKeyCheckInPlace
+	} else {
+		dupKeyCheck = optimizeDupKeyCheckForNormalInsert(e.Ctx().GetSessionVars(), txn)
+	}
+
 	for i, r := range toBeCheckedRows {
 		if r.handleKey != nil {
 			handle, err := tablecodec.DecodeRowKey(r.handleKey.newKey)
 			if err != nil {
 				return err
 			}
 
-			err = e.updateDupRow(ctx, i, txn, r, handle, e.OnDuplicate)
+			err = e.updateDupRow(ctx, i, txn, r, handle, e.OnDuplicate, dupKeyCheck)
 			if err == nil {
 				continue
 			}
@@ -260,7 +276,7 @@ func (e *InsertExec) batchUpdateDupRows(ctx context.Context, newRows [][]types.D
 			if handle == nil {
 				continue
 			}
-			err = e.updateDupRow(ctx, i, txn, r, handle, e.OnDuplicate)
+			err = e.updateDupRow(ctx, i, txn, r, handle, e.OnDuplicate, dupKeyCheck)
 			if err != nil {
 				if kv.IsErrNotFound(err) {
 					// Data index inconsistent? A unique key provide the handle information, but the
@@ -282,7 +298,8 @@ func (e *InsertExec) batchUpdateDupRows(ctx context.Context, newRows [][]types.D
 		// and key-values should be filled back to dupOldRowValues for the further row check,
 		// due to there may be duplicate keys inside the insert statement.
 		if newRows[i] != nil {
-			err := e.addRecord(ctx, newRows[i], table.DupKeyCheckDefault)
+			// TODO: seems we can optimize it to `DupKeyCheckSkip` all constraints are checked in previous steps.
+			err := e.addRecord(ctx, newRows[i], dupKeyCheck)
 			if err != nil {
 				return err
 			}
@@ -294,6 +311,25 @@ func (e *InsertExec) batchUpdateDupRows(ctx context.Context, newRows [][]types.D
 	return nil
 }
 
+// optimizeDupKeyCheckForNormalInsert trys to optimize the DupKeyCheckMode for an insert statement according to the
+// transaction and system variables.
+// If the DupKeyCheckMode of the current statement can be optimized, it will return `DupKeyCheckLazy` to avoid the
+// redundant requests to TiKV, otherwise, `DupKeyCheckInPlace` will be returned.
+// This method only works for "normal" insert statements, that means the options like "IGNORE" and "ON DUPLICATE KEY"
+// in a statement are not considerate, and callers should handle the above cases by themselves.
+func optimizeDupKeyCheckForNormalInsert(vars *variable.SessionVars, txn kv.Transaction) table.DupKeyCheckMode {
+	if !vars.ConstraintCheckInPlace || txn.IsPessimistic() || txn.IsPipelined() {
+		// We can just check duplicated key lazily without keys in storage for the below cases:
+		// - `txn.Pipelined()` is true.
+		//    It means the user is using `@@tidb_dml_type="bulk"` to insert rows in bulk mode.
+		//    DupKeyCheckLazy should be used to improve the performance.
+		// - The current transaction is pessimistic. The duplicate key check can be postponed to the lock stage.
+		// - The current transaction is optimistic but `tidb_constraint_check_in_place` is set to false.
+		return table.DupKeyCheckLazy
+	}
+	return table.DupKeyCheckInPlace
+}
+
 // Next implements the Executor Next interface.
 func (e *InsertExec) Next(ctx context.Context, req *chunk.Chunk) error {
 	req.Reset()
@@ -379,7 +415,7 @@ func (e *InsertExec) initEvalBuffer4Dup() {
 
 // doDupRowUpdate updates the duplicate row.
 func (e *InsertExec) doDupRowUpdate(ctx context.Context, handle kv.Handle, oldRow []types.Datum, newRow []types.Datum,
-	extraCols []types.Datum, cols []*expression.Assignment, idxInBatch int) error {
+	extraCols []types.Datum, cols []*expression.Assignment, idxInBatch int, dupKeyMode table.DupKeyCheckMode) error {
 	assignFlag := make([]bool, len(e.Table.WritableCols()))
 	// See http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 	e.curInsertVals.SetDatums(newRow...)
@@ -426,7 +462,7 @@ func (e *InsertExec) doDupRowUpdate(ctx context.Context, handle kv.Handle, oldRo
 	}
 
 	newData := e.row4Update[:len(oldRow)]
-	_, err := updateRecord(ctx, e.Ctx(), handle, oldRow, newData, assignFlag, e.Table, true, e.memTracker, e.fkChecks, e.fkCascades)
+	_, err := updateRecord(ctx, e.Ctx(), handle, oldRow, newData, assignFlag, e.Table, true, e.memTracker, e.fkChecks, e.fkCascades, dupKeyMode)
 	if err != nil {
 		return err
 	}
@@ -440,7 +476,7 @@ func (e *InsertExec) setMessage() {
 	if e.SelectExec != nil || numRecords > 1 {
 		numWarnings := stmtCtx.WarningCount()
 		var numDuplicates uint64
-		if stmtCtx.ErrGroupLevel(errctx.ErrGroupDupKey) != errctx.LevelError {
+		if e.IgnoreErr {
 			// if ignoreErr
 			numDuplicates = numRecords - stmtCtx.CopiedRows()
 		} else {

pkg/executor/insert_common.go

@@ -1412,15 +1412,11 @@ func (e *InsertValues) addRecordWithAutoIDHint(
 	ctx context.Context, row []types.Datum, reserveAutoIDCount int, dupKeyCheck table.DupKeyCheckMode,
 ) (err error) {
 	vars := e.Ctx().GetSessionVars()
-	if !vars.ConstraintCheckInPlace {
-		vars.PresumeKeyNotExists = true
-	}
 	if reserveAutoIDCount > 0 {
 		_, err = e.Table.AddRecord(e.Ctx().GetTableCtx(), row, table.WithCtx(ctx), table.WithReserveAutoIDHint(reserveAutoIDCount), dupKeyCheck)
 	} else {
 		_, err = e.Table.AddRecord(e.Ctx().GetTableCtx(), row, table.WithCtx(ctx), dupKeyCheck)
 	}
-	vars.PresumeKeyNotExists = false
 	if err != nil {
 		return err
 	}

pkg/executor/load_data.go

@@ -647,6 +647,11 @@ func (w *commitWorker) checkAndInsertOneBatch(ctx context.Context, rows [][]type
 	case ast.OnDuplicateKeyHandlingIgnore:
 		return w.batchCheckAndInsert(ctx, rows[0:cnt], w.addRecordLD, false)
 	case ast.OnDuplicateKeyHandlingError:
+		txn, err := w.Ctx().Txn(true)
+		if err != nil {
+			return err
+		}
+		dupKeyCheck := optimizeDupKeyCheckForNormalInsert(w.Ctx().GetSessionVars(), txn)
 		for i, row := range rows[0:cnt] {
 			sizeHintStep := int(w.Ctx().GetSessionVars().ShardAllocateStep)
 			if sizeHintStep > 0 && i%sizeHintStep == 0 {
@@ -655,9 +660,9 @@ func (w *commitWorker) checkAndInsertOneBatch(ctx context.Context, rows [][]type
 				if sizeHint > remain {
 					sizeHint = remain
 				}
-				err = w.addRecordWithAutoIDHint(ctx, row, sizeHint, table.DupKeyCheckDefault)
+				err = w.addRecordWithAutoIDHint(ctx, row, sizeHint, dupKeyCheck)
 			} else {
-				err = w.addRecord(ctx, row, table.DupKeyCheckDefault)
+				err = w.addRecord(ctx, row, dupKeyCheck)
 			}
 			if err != nil {
 				return err

pkg/executor/replace.go

@@ -63,7 +63,7 @@ func (e *ReplaceExec) Open(ctx context.Context) error {
 }
 
 // replaceRow removes all duplicate rows for one row, then inserts it.
-func (e *ReplaceExec) replaceRow(ctx context.Context, r toBeCheckedRow) error {
+func (e *ReplaceExec) replaceRow(ctx context.Context, r toBeCheckedRow, dupKeyCheck table.DupKeyCheckMode) error {
 	txn, err := e.Ctx().Txn(true)
 	if err != nil {
 		return err
@@ -106,7 +106,7 @@ func (e *ReplaceExec) replaceRow(ctx context.Context, r toBeCheckedRow) error {
 	}
 
 	// No duplicated rows now, insert the row.
-	err = e.addRecord(ctx, r.row, table.DupKeyCheckDefault)
+	err = e.addRecord(ctx, r.row, dupKeyCheck)
 	if err != nil {
 		return err
 	}
@@ -180,9 +180,12 @@ func (e *ReplaceExec) exec(ctx context.Context, newRows [][]types.Datum) error {
 	if e.stats != nil {
 		e.stats.Prefetch = time.Since(prefetchStart)
 	}
-	e.Ctx().GetSessionVars().StmtCtx.AddRecordRows(uint64(len(newRows)))
+	sessionVars := e.Ctx().GetSessionVars()
+	sessionVars.StmtCtx.AddRecordRows(uint64(len(newRows)))
+	// TODO: seems we can optimize it to `DupKeyCheckSkip` because all conflict rows are deleted in previous steps.
+	dupKeyCheck := optimizeDupKeyCheckForNormalInsert(sessionVars, txn)
 	for _, r := range toBeCheckedRows {
-		err = e.replaceRow(ctx, r)
+		err = e.replaceRow(ctx, r, dupKeyCheck)
 		if err != nil {
 			return err
 		}

pkg/executor/update.go

@@ -72,6 +72,8 @@ type UpdateExec struct {
 	fkChecks map[int64][]*FKCheckExec
 	// fkCascades contains the foreign key cascade. the map is tableID -> []*FKCascadeExec
 	fkCascades map[int64][]*FKCascadeExec
+
+	IgnoreError bool
 }
 
 // prepare `handles`, `tableUpdatable`, `changed` to avoid re-computations.
@@ -172,7 +174,7 @@ func (e *UpdateExec) merge(row, newData []types.Datum, mergeGenerated bool) erro
 	return nil
 }
 
-func (e *UpdateExec) exec(ctx context.Context, _ *expression.Schema, row, newData []types.Datum) error {
+func (e *UpdateExec) exec(ctx context.Context, _ *expression.Schema, row, newData []types.Datum, dupKeyCheck table.DupKeyCheckMode) error {
 	defer trace.StartRegion(ctx, "UpdateExec").End()
 	bAssignFlag := make([]bool, len(e.assignFlag))
 	for i, flag := range e.assignFlag {
@@ -205,7 +207,7 @@ func (e *UpdateExec) exec(ctx context.Context, _ *expression.Schema, row, newDat
 		// Update row
 		fkChecks := e.fkChecks[content.TblID]
 		fkCascades := e.fkCascades[content.TblID]
-		changed, err1 := updateRecord(ctx, e.Ctx(), handle, oldData, newTableData, flags, tbl, false, e.memTracker, fkChecks, fkCascades)
+		changed, err1 := updateRecord(ctx, e.Ctx(), handle, oldData, newTableData, flags, tbl, false, e.memTracker, fkChecks, fkCascades, dupKeyCheck)
 		if err1 == nil {
 			_, exist := e.updatedRowKeys[content.Start].Get(handle)
 			memDelta := e.updatedRowKeys[content.Start].Set(handle, changed)
@@ -273,6 +275,27 @@ func (e *UpdateExec) updateRows(ctx context.Context) (int, error) {
 	}
 	memUsageOfChk := int64(0)
 	totalNumRows := 0
+
+	txn, err := e.Ctx().Txn(true)
+	if err != nil {
+		return 0, err
+	}
+
+	dupKeyCheck := table.DupKeyCheckInPlace
+	if (txn.IsPessimistic() && !e.IgnoreError) || txn.IsPipelined() {
+		// - If `txn.Pipelined()`, it means current is using `@@tidb_dml_type="bulk"` to insert rows.
+		//   `DupKeyCheckLazy` should be used in "bulk" mode to avoid request storage and improve the performance.
+		// - If `txn.IsPessimistic()`, we can use `DupKeyCheckLazy` to postpone the storage constraints check
+		//   to subsequence stages such as lock.
+		//   One exception is `UPDATE IGNORE ...`, `DupKeyCheckInPlace` should be used to ensure executor can get the
+		//   dup-key error immediately and ignore it then.
+		// - If the current txn is optimistic, `DupKeyCheckInPlace` is always used
+		//   even if `tidb_constraint_check_in_place` is `OFF`.
+		//   This is because `tidb_constraint_check_in_place` is only designed for insert cases, see comments in issue:
+		//   https://github.com/pingcap/tidb/issues/54492#issuecomment-2229941881
+		dupKeyCheck = table.DupKeyCheckLazy
+	}
+
 	for {
 		e.memTracker.Consume(-memUsageOfChk)
 		err := exec.Next(ctx, e.Children(0), chk)
@@ -286,14 +309,12 @@ func (e *UpdateExec) updateRows(ctx context.Context) (int, error) {
 		memUsageOfChk = chk.MemoryUsage()
 		e.memTracker.Consume(memUsageOfChk)
 		if e.collectRuntimeStatsEnabled() {
-			txn, err := e.Ctx().Txn(true)
-			if err == nil && txn.GetSnapshot() != nil {
-				txn.GetSnapshot().SetOption(kv.CollectRuntimeStats, e.stats.SnapshotRuntimeStats)
+			if snap := txn.GetSnapshot(); snap != nil {
+				snap.SetOption(kv.CollectRuntimeStats, e.stats.SnapshotRuntimeStats)
 			}
 		}
-		txn, err := e.Ctx().Txn(true)
 		// pipelined dml may already flush in background, don't touch it to avoid race.
-		if err == nil && !txn.IsPipelined() {
+		if !txn.IsPipelined() {
 			sc := e.Ctx().GetSessionVars().StmtCtx
 			txn.SetOption(kv.ResourceGroupTagger, sc.GetResourceGroupTagger())
 			if sc.KvExecCounter != nil {
@@ -329,7 +350,7 @@ func (e *UpdateExec) updateRows(ctx context.Context) (int, error) {
 				}
 			}
 			// write to table
-			if err := e.exec(ctx, e.Children(0).Schema(), datumRow, newRow); err != nil {
+			if err := e.exec(ctx, e.Children(0).Schema(), datumRow, newRow, dupKeyCheck); err != nil {
 				return 0, err
 			}
 		}

pkg/executor/write.go

@@ -56,7 +56,7 @@ var (
 func updateRecord(
 	ctx context.Context, sctx sessionctx.Context, h kv.Handle, oldData, newData []types.Datum, modified []bool,
 	t table.Table,
-	onDup bool, _ *memory.Tracker, fkChecks []*FKCheckExec, fkCascades []*FKCascadeExec,
+	onDup bool, _ *memory.Tracker, fkChecks []*FKCheckExec, fkCascades []*FKCascadeExec, dupKeyMode table.DupKeyCheckMode,
 ) (bool, error) {
 	r, ctx := tracing.StartRegionEx(ctx, "executor.updateRecord")
 	defer r.End()
@@ -179,7 +179,7 @@ func updateRecord(
 				return false, err
 			}
 
-			_, err = t.AddRecord(sctx.GetTableCtx(), newData, table.IsUpdate, table.WithCtx(ctx))
+			_, err = t.AddRecord(sctx.GetTableCtx(), newData, table.IsUpdate, table.WithCtx(ctx), dupKeyMode)
 			if err != nil {
 				return false, err
 			}
@@ -199,9 +199,9 @@ func updateRecord(
 			// If InHandleForeignKeyTrigger or ForeignKeyTriggerCtx.HasFKCascades is true indicate we may have
 			// foreign key cascade need to handle later, then we still need to write index value,
 			// otherwise, the later foreign cascade executor may see data-index inconsistency in txn-mem-buffer.
-			opts = []table.UpdateRecordOption{table.WithCtx(ctx)}
+			opts = []table.UpdateRecordOption{table.WithCtx(ctx), dupKeyMode}
 		} else {
-			opts = []table.UpdateRecordOption{table.WithCtx(ctx), table.SkipWriteUntouchedIndices}
+			opts = []table.UpdateRecordOption{table.WithCtx(ctx), dupKeyMode, table.SkipWriteUntouchedIndices}
 		}
 
 		// Update record to new value and update index.

pkg/planner/core/common_plans.go

@@ -371,6 +371,7 @@ type Insert struct {
 	SelectPlan base.PhysicalPlan
 
 	IsReplace bool
+	IgnoreErr bool
 
 	// NeedFillDefaultValue is true when expr in value list reference other column.
 	NeedFillDefaultValue bool
@@ -432,6 +433,8 @@ type Update struct {
 
 	AllAssignmentsAreConstant bool
 
+	IgnoreError bool
+
 	VirtualAssignmentsOffset int
 
 	SelectPlan base.PhysicalPlan