Delete Large data from Sharepoint Lists

This post contains code to delete the litems from a sharepoint list having very large data.
In one of my projects, I was storing very large amount of data in a list that I require to delete after specific number of days.  I tried deleting the data using SPListItemcollection but that seems to be too heavy for getting all the items in memory and delete those one by one. So I used inbuilt method of SPWeb object which processes the information for bulk data. You can make use of SPWeb's
ProcessBatchData method which takes in an XML string and processes the query as per the command specified in XML. I have done it for "Delete" however there are other methods too which are supported.

Below is the code snippet for deleting bulk data from a large list.

private void DeleteListItems(String listName)

        {
            SPWeb objWeb = SPContext.Current.Web;
            StringBuilder sbDelete = new StringBuilder();

            SPList list = objWeb.Lists[listName];

            SPQuery objSPQuery = newSPQuery();

            SPQuery query;

            SPSiteDataQuery objSPSiteDataQuery;

            String listGuid = list.ID.ToString();

            Int32 itemcount = list.ItemCount;

            //Create an XML to be send to ProcessBatchData method of SPWeb

            sbDelete.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?><Batch>");

            //String with specified format

            String command = String.Format("<Method><SetList Scope=\"Request\">{0}</SetList><SetVar Name=\"ID\">{{0}}</SetVar><SetVar Name=\"Cmd\">Delete</SetVar></Method>", listGuid);

            if (itemcount < 1000)

            {
                //Process simple delete if items < 1000
                DataTable objDataTable = null;
                query = new SPQuery();
                objSPSiteDataQuery = new SPSiteDataQuery();
                objSPSiteDataQuery.ViewFields = "<FieldRef Name=\"ID\" />";
                objSPSiteDataQuery.Lists = "<Lists><List ID=\"" + listGuid + "\" /></Lists>";
                //building a void query for getting results
                objSPSiteDataQuery.Query = "<Where><IsNotNull><FieldRef Name='ID' /></IsNotNull></Where>";
               
                objDataTable = objWeb.GetSiteData(objSPSiteDataQuery);
                if (objDataTable != null && objDataTable.Rows.Count > 0)
                {
                    foreach (DataRow row in objDataTable.Rows)
                    {
                        sbDelete.Append(string.Format(command, Convert.ToString(row["ID"])));
                    }
                }
                sbDelete.Append("</Batch>");
                objWeb.ProcessBatchData(sbDelete.ToString());
                            list.Update();
            }
            else
            {
              for (int batchCount = 0; batchCount < itemcount / 1000; batchCount++)
              {
                    DataTable objDataTable = null;
                    query = new SPQuery();
                    objSPSiteDataQuery = new SPSiteDataQuery();
                    objSPSiteDataQuery.ViewFields = "<FieldRef Name=\"ID\" />";
                    objSPSiteDataQuery.RowLimit = 1000;
                    objSPSiteDataQuery.Lists = "<Lists><List ID=\"" + listGuid + "\" /></Lists>";
                   objSPSiteDataQuery.Query = "<Where><IsNotNull><FieldRef Name='ID' /></IsNotNull></Where>";
                    objDataTable = objWeb.GetSiteData(objSPSiteDataQuery);
                    //Using here Site data query since it retrieves dataset instead of SPListItemCollection which is much Lighter

                    if (objDataTable != null && objDataTable.Rows.Count > 0)

                    {
                        foreach (DataRow row in objDataTable.Rows)
                         {
                          sbDelete.Append(string.Format(command, Convert.ToString(row["ID"])));
                        }
                        sbDelete.Append("</Batch>");
                        //Execute the batch job for deleting items
                        objWeb.ProcessBatchData(sbDelete.ToString());
                        list.Update();

                        //re initialise the string builder to add new XML
                        sbDelete = new StringBuilder();
                        sbDelete.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?><Batch>");
                    }
               }
            }
}