*: remove the LightningMode from TiDB (#12466)

executor/insert.go

@@ -51,15 +51,12 @@ func (e *InsertExec) exec(ctx context.Context, rows [][]types.Datum) error {
 	defer sessVars.CleanBuffers()
 	ignoreErr := sessVars.StmtCtx.DupKeyAsWarning
 
-	if !sessVars.LightningMode {
-		txn, err := e.ctx.Txn(true)
-		if err != nil {
-			return err
-		}
-		sessVars.GetWriteStmtBufs().BufStore = kv.NewBufferStore(txn, kv.TempTxnMemBufCap)
+	txn, err := e.ctx.Txn(true)
+	if err != nil {
+		return err
 	}
-
-	e.ctx.GetSessionVars().StmtCtx.AddRecordRows(uint64(len(rows)))
+	sessVars.GetWriteStmtBufs().BufStore = kv.NewBufferStore(txn, kv.TempTxnMemBufCap)
+	sessVars.StmtCtx.AddRecordRows(uint64(len(rows)))
 	// If you use the IGNORE keyword, duplicate-key error that occurs while executing the INSERT statement are ignored.
 	// For example, without IGNORE, a row that duplicates an existing UNIQUE index or PRIMARY KEY value in
 	// the table causes a duplicate-key error and the statement is aborted. With IGNORE, the row is discarded and no error occurs.

executor/insert_common.go

@@ -396,13 +396,11 @@ func (e *InsertValues) doBatchInsert(ctx context.Context) error {
 		// We should return a special error for batch insert.
 		return ErrBatchInsertFail.GenWithStack("BatchInsert failed with error: %v", err)
 	}
-	if !sessVars.LightningMode {
-		txn, err := e.ctx.Txn(true)
-		if err != nil {
-			return err
-		}
-		sessVars.GetWriteStmtBufs().BufStore = kv.NewBufferStore(txn, kv.TempTxnMemBufCap)
+	txn, err := e.ctx.Txn(true)
+	if err != nil {
+		return err
 	}
+	sessVars.GetWriteStmtBufs().BufStore = kv.NewBufferStore(txn, kv.TempTxnMemBufCap)
 	return nil
 }
 

executor/prepared.go

@@ -173,7 +173,7 @@ func (e *PrepareExec) Next(ctx context.Context, req *chunk.Chunk) error {
 		Params:        sorter.markers,
 		SchemaVersion: e.is.SchemaMetaVersion(),
 	}
-	prepared.UseCache = plannercore.PreparedPlanCacheEnabled() && (vars.LightningMode || plannercore.Cacheable(stmt))
+	prepared.UseCache = plannercore.PreparedPlanCacheEnabled() && plannercore.Cacheable(stmt)
 
 	// We try to build the real statement of preparedStmt.
 	for i := range prepared.Params {

kv/buffer_store.go

@@ -20,8 +20,6 @@ import (
 var (
 	// DefaultTxnMembufCap is the default transaction membuf capability.
 	DefaultTxnMembufCap = 4 * 1024
-	// ImportingTxnMembufCap is the capability of tidb importing data situation.
-	ImportingTxnMembufCap = 32 * 1024
 	// TempTxnMemBufCap is the capability of temporary membuf.
 	TempTxnMemBufCap = 64
 )

session/session.go

@@ -246,10 +246,6 @@ func (s *session) DDLOwnerChecker() owner.DDLOwnerChecker {
 }
 
 func (s *session) getMembufCap() int {
-	if s.sessionVars.LightningMode {
-		return kv.ImportingTxnMembufCap
-	}
-
 	return kv.DefaultTxnMembufCap
 }
 

sessionctx/variable/session.go

@@ -306,9 +306,6 @@ type SessionVars struct {
 
 	/* TiDB system variables */
 
-	// LightningMode is true when the lightning use the kvencoder to transfer sql to raw kv.
-	LightningMode bool
-
 	// SkipUTF8Check check on input value.
 	SkipUTF8Check bool
 
@@ -593,9 +590,7 @@ func (s *SessionVars) GetSplitRegionTimeout() time.Duration {
 
 // CleanBuffers cleans the temporary bufs
 func (s *SessionVars) CleanBuffers() {
-	if !s.LightningMode {
-		s.GetWriteStmtBufs().clean()
-	}
+	s.GetWriteStmtBufs().clean()
 }
 
 // AllocPlanColumnID allocates column id for plan.

table/tables/index.go

@@ -198,9 +198,10 @@ func (c *index) Create(sctx sessionctx.Context, rm kv.RetrieverMutator, indexedV
 		fn(&opt)
 	}
 	ss := opt.AssertionProto
-	writeBufs := sctx.GetSessionVars().GetWriteStmtBufs()
-	skipCheck := sctx.GetSessionVars().LightningMode || sctx.GetSessionVars().StmtCtx.BatchCheck
-	key, distinct, err := c.GenIndexKey(sctx.GetSessionVars().StmtCtx, indexedValues, h, writeBufs.IndexKeyBuf)
+	vars := sctx.GetSessionVars()
+	writeBufs := vars.GetWriteStmtBufs()
+	skipCheck := vars.StmtCtx.BatchCheck
+	key, distinct, err := c.GenIndexKey(vars.StmtCtx, indexedValues, h, writeBufs.IndexKeyBuf)
 	if err != nil {
 		return 0, err
 	}

table/tables/tables.go

@@ -413,10 +413,6 @@ func adjustRowValuesBuf(writeBufs *variable.WriteStmtBufs, rowLen int) {
 // getRollbackableMemStore get a rollbackable BufferStore, when we are importing data,
 // Just add the kv to transaction's membuf directly.
 func (t *tableCommon) getRollbackableMemStore(ctx sessionctx.Context) (kv.RetrieverMutator, error) {
-	if ctx.GetSessionVars().LightningMode {
-		return ctx.Txn(true)
-	}
-
 	bs := ctx.GetSessionVars().GetWriteStmtBufs().BufStore
 	if bs == nil {
 		txn, err := ctx.Txn(true)
@@ -528,12 +524,10 @@ func (t *tableCommon) AddRecord(ctx sessionctx.Context, r []types.Datum, opts ..
 	}
 	txn.SetAssertion(key, kv.None)
 
-	if !sessVars.LightningMode {
-		if err = rm.(*kv.BufferStore).SaveTo(txn); err != nil {
-			return 0, err
-		}
-		ctx.StmtAddDirtyTableOP(table.DirtyTableAddRow, t.physicalTableID, recordID)
+	if err = rm.(*kv.BufferStore).SaveTo(txn); err != nil {
+		return 0, err
 	}
+	ctx.StmtAddDirtyTableOP(table.DirtyTableAddRow, t.physicalTableID, recordID)
 
 	if shouldWriteBinlog(ctx) {
 		// For insert, TiDB and Binlog can use same row and schema.
@@ -594,7 +588,7 @@ func (t *tableCommon) addIndices(sctx sessionctx.Context, recordID int64, r []ty
 	} else {
 		ctx = context.Background()
 	}
-	skipCheck := sctx.GetSessionVars().LightningMode || sctx.GetSessionVars().StmtCtx.BatchCheck
+	skipCheck := sctx.GetSessionVars().StmtCtx.BatchCheck
 	if t.meta.PKIsHandle && !skipCheck && !opt.SkipHandleCheck {
 		if err := CheckHandleExists(ctx, sctx, t, recordID, nil); err != nil {
 			return recordID, err