Some times you need to return a set of data from a WCF service and When you are working with, dataset is the obvious reason you wish at your client side. But passing dataset can make service less interoportable because in that case you are forced to use dataset on your client code. Second point is that dataset might become very bulky as per size of the data grows. Instead, passing dataset we can pass compressed byte array of dataset from WCF service and consume it like a byte array on client end. After Uncompression, either you can convert it into dataset or you can use this XML in any other form you want.

For this, lets first create a WCF service:

public byte[] GetEmployee(string BranchId)
string sQ = "Select EmpId, EmployeeName from EmployeeMaster";

SqlConnection objConn = new SqlConnection("Data Source=[YourServer];Initial Catalog=[Database];User ID=[UserName];Password=[Password];MultipleActiveResultSets=True");
SqlCommand objCom = new SqlCommand(sQ, objConn);
SqlDataAdapter objDa = new SqlDataAdapter(objCom);
DataSet objDs = new DataSet();
//Now we'll convert dataset into byte array and compress it using gzStream.
byte[] binaryDataResult = null;
MemoryStream memStream = new MemoryStream();
GZipStream gzStream = new GZipStream(memStream, CompressionMode.Compress);
binaryDataResult = memStream.ToArray();
return binaryDataResult;

Here, We are first filling dataset from database then after compression using GZipStream, we are converting it to byte array. At client end we will get this byte array and we'll again follow these steps in reverse order.

ServiceClient s = new ServiceClient();
byte[] btEmployee = (byte[])s.GetEmployee("0");
if (btEmployee != null)
MemoryStream mEmployee = new MemoryStream(btEmployee);
GZipStream gStreamEmployee = new GZipStream(mEmployee, CompressionMode.Decompress);
DataSet objDsEmployee = new DataSet();
gvEmployee.DataSource = objDsEmployee;