How to Switch Database Connection Mysqli or Postgres ??

Hi,

I need to Connect Mysqli Or Postgres in Database Connection.I need to Connect Both are default Option how done ??

We can find driver When query loaded ??

For Example :

Code:

if($db_driver == 'mysqli')
{

$db['default'] = array(
);
}
if($db_driver == 'postgres')
{

$db['default'] = array(
);
}

Is it possible to do like above or any other option to run both database connect in Default database.

Please Give me solution for my problem.

Geetha