diff --git a/writeengine/server/we_dmlcommandproc.cpp b/writeengine/server/we_dmlcommandproc.cpp
index 5da10433e..a6c5b025c 100644
--- a/writeengine/server/we_dmlcommandproc.cpp
+++ b/writeengine/server/we_dmlcommandproc.cpp
@@ -102,13 +102,13 @@ uint8_t WE_DMLCommandProc::processSingleInsert(messageqcpp::ByteStream& bs, std:
     bs >> tmp32;
     uint32_t dbroot = tmp32;
 
-    //cout << "processSingleInsert received bytestream length " << bs.length() << endl;
+    cout << "processSingleInsert received bytestream length " << bs.length() << endl;
 
     messageqcpp::ByteStream::byte packageType;
     bs >> packageType;
     insertPkg.read( bs);
     uint32_t sessionId = insertPkg.get_SessionID();
-    //cout << " processSingleInsert for session " << sessionId << endl;
+    cout << " processSingleInsert for session " << sessionId << endl;
     DMLTable* tablePtr = insertPkg.get_Table();
     RowList rows = tablePtr->get_RowList();
 
diff --git a/writeengine/shared/.we_fileop.h.swo b/writeengine/shared/.we_fileop.h.swo
new file mode 100644
index 000000000..46e47f43e
Binary files /dev/null and b/writeengine/shared/.we_fileop.h.swo differ
diff --git a/writeengine/shared/we_fileop.cpp b/writeengine/shared/we_fileop.cpp
index f77817962..e08bea3fb 100644
--- a/writeengine/shared/we_fileop.cpp
+++ b/writeengine/shared/we_fileop.cpp
@@ -63,7 +63,6 @@ namespace WriteEngine
 /*static*/ boost::mutex               FileOp::m_createDbRootMutexes;
 /*static*/ boost::mutex               FileOp::m_mkdirMutex;
 /*static*/ std::map<int, boost::mutex*> FileOp::m_DbRootAddExtentMutexes;
-const int MAX_NBLOCKS = 8192; // max number of blocks written to an extent
 // in 1 call to fwrite(), during initialization
 
 //StopWatch timer;
diff --git a/writeengine/shared/we_fileop.h b/writeengine/shared/we_fileop.h
index 67d926910..175b3fb0d 100644
--- a/writeengine/shared/we_fileop.h
+++ b/writeengine/shared/we_fileop.h
@@ -50,6 +50,8 @@
 #define EXPORT
 #endif
 
+#define MAX_NBLOCKS 8192
+
 #include "brmtypes.h"
 
 /** Namespace WriteEngine */
diff --git a/writeengine/wrapper/we_colop.cpp b/writeengine/wrapper/we_colop.cpp
index 56c1b923a..067453b87 100644
--- a/writeengine/wrapper/we_colop.cpp
+++ b/writeengine/wrapper/we_colop.cpp
@@ -35,6 +35,7 @@ using namespace std;
 #include "idbcompress.h"
 #include "writeengine.h"
 #include "cacheutils.h"
+#include "we_fileop.h"
 
 using namespace execplan;
 
@@ -471,6 +472,13 @@ int ColumnOp::allocRowId(const TxnID& txnid, bool useStartingExtent,
             if ( rc != NO_ERROR)
                 return rc;
 
+            // MCOL-498 Fill up the first block with empty values.
+            {
+                uint64_t emptyVal = getEmptyRowValue(column.colDataType, column.colWidth);
+                setEmptyBuf(buf, BYTE_PER_BLOCK, emptyVal, column.colWidth);
+            }
+
+
             for (j = 0; j < totalRowPerBlock; j++)
             {
                 if (isEmptyRow(buf, j, column))
@@ -1536,12 +1544,14 @@ int ColumnOp::writeRow(Column& curCol, uint64_t totalRow, const RID* rowIdArray,
     int rc = NO_ERROR;
     bool fillUpWEmptyVals = false;
     bool fistRowInBlock = false;
+    bool lastRowInBlock = false;
+    uint16_t rowsInBlock = BYTE_PER_BLOCK / curCol.colWidth;
 
     while (!bExit)
     {
         curRowId = rowIdArray[i];
 
-        calculateRowId(curRowId, BYTE_PER_BLOCK / curCol.colWidth, curCol.colWidth, dataFbo, dataBio);
+        calculateRowId(curRowId, rowsInBlock, curCol.colWidth, dataFbo, dataBio);
 
         // load another data block if necessary
         if (curDataFbo != dataFbo)
@@ -1562,7 +1572,7 @@ int ColumnOp::writeRow(Column& curCol, uint64_t totalRow, const RID* rowIdArray,
 
             // MCOL-498 CS hasn't touched any block yet,
             // but the row fill be the first in the block.
-            fistRowInBlock = ( !(curRowId % (BYTE_PER_BLOCK / curCol.colWidth)) ) ? true : false;
+            fistRowInBlock = ( !(curRowId % (rowsInBlock)) ) ? true : false;
             if( fistRowInBlock && !bDelete )
                 fillUpWEmptyVals = true;
 
@@ -1696,11 +1706,48 @@ int ColumnOp::writeRow(Column& curCol, uint64_t totalRow, const RID* rowIdArray,
             int writeSize = BYTE_PER_BLOCK - ( dataBio + curCol.colWidth );
             // MCOL-498 Add the check though this is unlikely at the moment of writing.
             if ( writeSize )
-                setEmptyBuf( dataBuf + dataBio + curCol.colWidth, writeSize, emptyVal, curCol.colWidth );
-            fillUpWEmptyVals = false;
-            fistRowInBlock = false;
+                setEmptyBuf( dataBuf + dataBio + curCol.colWidth, writeSize,
+                            emptyVal, curCol.colWidth );
+            //fillUpWEmptyVals = false;
+            //fistRowInBlock = false;
         }
+
         rc = saveBlock(curCol.dataFile.pFile, dataBuf, curDataFbo);
+
+        if ( rc != NO_ERROR)
+            return rc;
+
+        // MCOL-498 If it was the last row in a block fill the next block with 
+        // empty vals, otherwise next ColumnOp::allocRowId()
+        // will fail on the next block.
+        lastRowInBlock = ( rowsInBlock - ( curRowId % rowsInBlock ) == 1 ) ? true : false;
+        if ( lastRowInBlock )
+        {
+            if( !fillUpWEmptyVals )
+                emptyVal = getEmptyRowValue(curCol.colDataType, curCol.colWidth);
+            // MCOL-498 Skip if this is the last block in an extent.
+            if ( curDataFbo !=  MAX_NBLOCKS - 1)
+            {
+                rc = saveBlock(curCol.dataFile.pFile, dataBuf, curDataFbo);
+                if ( rc != NO_ERROR)
+                    return rc;
+
+                curDataFbo += 1;
+                rc = readBlock(curCol.dataFile.pFile, dataBuf, curDataFbo);
+                if ( rc != NO_ERROR)
+                    return rc;
+
+                unsigned char zeroSubBlock[BYTE_PER_SUBBLOCK];
+                std::memset(zeroSubBlock, 0, BYTE_PER_SUBBLOCK);
+                // The first subblock is made of 0 - fill the block with empty vals.
+                if ( !std::memcmp(dataBuf, zeroSubBlock, BYTE_PER_SUBBLOCK) )
+                {
+                    setEmptyBuf(dataBuf, BYTE_PER_BLOCK, emptyVal, curCol.colWidth);
+                    rc = saveBlock(curCol.dataFile.pFile, dataBuf, curDataFbo);
+                }
+            }
+        }
+
     }
     return rc;
 }