a need for a custom field

Hi
Image , Title and description are not enough as there is always a need for #hashtags on social medias, without # social medias post are useless

if you don't add this feature in a future release please can you tell me where in the (SQL) code I can add a custom field ?

in each adapter.php there is a function :
public function addPost($title, $link, $desc = '', $image = '')
I need :
public function addPost($title, $link, $desc = '', $image = '', $tags='')

where is the main function that load the fields , ill add myself the SQL query too load hashtags ?

thank you