design of bulk UPSERT (aka MERGE): update_or_insert

Stack Overflow and various forums are rife with questions about how to
efficiently update or insert ActiveRecords into a table. (In fact, one
of my earliest questions to this forum was on this very topic.)

My recent work regularly calls for an efficient "update or insert"
method for tens of thousands of records. After a fair amount of
googling, I don't see a generalized solution, so I've decided to design
and implement the function for real. In this note, I'm proposing a
design specifically for critique and feedback.

(First question: are there other forums where I should be posing this

A typical use case might look like this:

hey ff,

You might want to take a look at
- released same week you posted this.


Hello there
I am not familiar with MongoDB but i think here is a possible resource.
hope it will help you...