diff --git a/src/main/java/org/apache/sysds/runtime/frame/data/FrameBlock.java b/src/main/java/org/apache/sysds/runtime/frame/data/FrameBlock.java
index 668d2a71d20..79393cd4834 100644
--- a/src/main/java/org/apache/sysds/runtime/frame/data/FrameBlock.java
+++ b/src/main/java/org/apache/sysds/runtime/frame/data/FrameBlock.java
@@ -937,10 +937,10 @@ public boolean isShallowSerialize() {
 	public boolean isShallowSerialize(boolean inclConvert) {
 		// shallow serialize if non-string schema because a frame block
 		// is always dense but strings have large array overhead per cell
-		boolean ret = true;
-		for(int j = 0; j < _schema.length && ret; j++)
-			ret &= _coldata[j].isShallowSerialize();
-		return ret;
+		for(int j = 0; j < _schema.length; j++)
+			if(!_coldata[j].isShallowSerialize())
+				return false;
+		return true;
 	}
 
 	@Override
diff --git a/src/main/java/org/apache/sysds/runtime/frame/data/columns/StringArray.java b/src/main/java/org/apache/sysds/runtime/frame/data/columns/StringArray.java
index 3ddb18354f8..5416841456b 100644
--- a/src/main/java/org/apache/sysds/runtime/frame/data/columns/StringArray.java
+++ b/src/main/java/org/apache/sysds/runtime/frame/data/columns/StringArray.java
@@ -661,7 +661,7 @@ else if(ls.equals("false") || ls.equals("f"))
 
 	@Override
 	public boolean isShallowSerialize() {
-		long s = getInMemorySize();
+		final long s = getInMemorySize();
 		return _size < 100 || s / _size < 100;
 	}
 
diff --git a/src/main/java/org/apache/sysds/runtime/matrix/data/MatrixBlock.java b/src/main/java/org/apache/sysds/runtime/matrix/data/MatrixBlock.java
index 177be11b023..bc1476a578d 100644
--- a/src/main/java/org/apache/sysds/runtime/matrix/data/MatrixBlock.java
+++ b/src/main/java/org/apache/sysds/runtime/matrix/data/MatrixBlock.java
@@ -2939,13 +2939,14 @@ public boolean isShallowSerialize(boolean inclConvert) {
 		boolean sparseDst = evalSparseFormatOnDisk();
 		return !sparse || !sparseDst
 			|| (sparse && sparseBlock instanceof SparseBlockCSR)
-			|| (sparse && sparseBlock instanceof SparseBlockMCSR
-				&& getInMemorySize() / MAX_SHALLOW_SERIALIZE_OVERHEAD 
-				<= getExactSerializedSize())
-			|| (sparse && sparseBlock instanceof SparseBlockMCSR
-				&& nonZeros < Integer.MAX_VALUE //CSR constraint
-				&& inclConvert && CONVERT_MCSR_TO_CSR_ON_DEEP_SERIALIZE
-				&& !isUltraSparseSerialize(sparseDst));
+			|| (sparse && sparseBlock instanceof SparseBlockMCSR);
+			// || (sparse && sparseBlock instanceof SparseBlockMCSR
+			// 	&& getInMemorySize() / MAX_SHALLOW_SERIALIZE_OVERHEAD 
+			// 	<= getExactSerializedSize())
+			// || (sparse && sparseBlock instanceof SparseBlockMCSR
+			// 	&& nonZeros < Integer.MAX_VALUE //CSR constraint
+			// 	&& inclConvert && CONVERT_MCSR_TO_CSR_ON_DEEP_SERIALIZE
+			// 	&& !isUltraSparseSerialize(sparseDst));
 	}
 	
 	@Override