How to add tables/fiels to DB

[odsnet]

Hello,

I'd like to write a plugin which stores something (related to a thread) in the database. So I'd like to extend the thread table for one field. If that isn't possible I could add another table where the extra data is stored. but then I've got to make sure that this table cascades on delete and so on.
How could I alter the Thread table with the VB API in a plugin?

I found how to add a field to the form here: https://vborg.vbsupport.ru/showthread.php?t=237982 but it shouldn't be appended to the posting but stored in an extra field.

Best regards,
Heiko