add documentation for enableRowBatchSize flag

update

cc

batch_writer.go

@@ -107,7 +107,7 @@ func (w *BatchWriter) WriteRowBatch(batch *RowBatch) error {
 			if w.EnforceInlineVerification {
 				// This code should only be active if the InlineVerifier background
 				// reverification is not occuring. An example of this would be when you
-				// run the BatchWriter as a part of copying the primary table or delta
+				// run the BatchWriter as a part of copying the primary table or the delta
 				// copying the joined table.
 				if len(mismatches) > 0 {
 					tx.Rollback()

config.go

@@ -716,6 +716,11 @@ type Config struct {
 	// EnableRowBatchsize is used to enable or disable the calculation of number of bytes written for each row batch.
 	//
 	// Optional: Defaults to false.
+	//
+	// NOTE:
+	// Turning off the EnableRowBatchSize flag would show the NumBytes written per RowBatch to be zero
+	// in the Progress. This behaviour is perfectly okay and doesn't mean there are no rows being written
+	// to the target DB.
 	EnableRowBatchSize bool
 }