How to delete data permanently in DBF file ?

Question

OleDbConnection oleDbConnection = new OleDbConnection("Provider=VFPOLEDB.1;Data Source=" + filePath + ";");
oleDbConnection.Open();
string sql = "Delete From CLIENTS";
OleDbCommand oleDbCommand = new OleDbCommand(sql, oleDbConnection);
oleDbCommand.ExecuteNonQuery();
oleDbConnection.Close();

When I use the above code it will delete all the records but not permanently. All the records are present physically in the DBF file. So how to delete all data parmanemtly ?