lightning failed to log encoding error

[lance6716]

tidb/br/pkg/lightning/backend/kv/base.go

Lines 286 to 294 in ce9c0b9

	func (e *BaseKVEncoder) LogKVConvertFailed(row []types.Datum, j int, colInfo *model.ColumnInfo, err error) error {
	var original types.Datum
	if 0 <= j && j < len(row) {
	original = row[j]
	row = row[j : j+1]
	}
	e.logger.Error("kv convert failed",
	zap.Array("original", RowArrayMarshaller(row)),

When the source file has ill-formated row, the row is very large so it can't be logged. We can't locate the bad row

2023-06-01 10:55:27.887067902 +0800 CST m=+35.508861459 write error: write length 20297970322 exceeds maximum file size 536870912