What is the best method of adding new attributes to the sales and/or quote tables in magento via an install script:
use: addColumn() or use addAttribute() ?
So the main questions are :
What is the best if in the future I need to migrate to a new version (I m on CE 1.7) ? What is the best for performance ?
I need to display this custom data in the admin back end order grid, so what is the best choice for that too (performance & usability) ?
Thank you in advance !