download backpus as plain sql file

application/controllers/config.php

@@ -133,18 +133,13 @@ class Config extends Secure_area
     	{
     		$this->load->dbutil();
     		$prefs = array(
-    				'format'      => 'gzip',
+    				'format'      => 'txt',
     				'filename'    => 'ospos.sql'
     		);
     		 
     		$backup = $this->dbutil->backup($prefs);
     		 
-    		$file_name =  'ospos-' . date("Y-m-d-H-i-s") .'.gz';
-    		$save = 'uploads/'.$file_name;
-    		 
-    		$this->load->helper('file');
-    		write_file($save, $backup);
-    		 
+    		$file_name =  'ospos-' . date("Y-m-d-H-i-s") .'.sql';
     		$this->load->helper('download');
     		force_download($file_name, $backup);
     	}

system/helpers/download_helper.php

@@ -97,7 +97,6 @@ if ( ! function_exists('force_download'))
 			header('Pragma: no-cache');
 			header("Content-Length: ".strlen($data));
 		}
-		ob_clean();
 		exit($data);
 	}
 }