Rails - Nov 2006 - Model.delete_all vs Model.destroy_all in a habtm

Hi there

I have an habtm association between 2 Models.

I regularly have to truncate the table on one side of the relationship
and repopulate the table with a fresh csv file.

I notice that f I do Model.delete_all, none of the records in my habtm
join table get deleted, whereas if I use destroy_all they do.

However, the overhead of using destroy_all is too great. For the
amount of records I have to deal with, destroy_all is very processor
and time intensive.

How best to quickly truncate one side of the habtm relationship *and*
the intermediate join table?

I suppose I can drop to connection.execute and truncate that way, but
that does not seem very Rails like.

Any clues appreciated.

Richard