On Mon, Oct 20, 2014 at 1:03 AM, Anshuman Aggarwal
<anshuman.aggar...@gmail.com> wrote:
> The idea of having a .update() ORM construct is to be able to do this
> without having to fall down to a manual transaction every time, otherwise
> why have a DB level <qs>.update()...I am sure the performance of above
> pseudo code would be about the same (or sufficiently small as to be
> ignorable)...


i'm sure it's far from ignorable.  <qs>.update() generates an UPDATE
... WHERE ... statement, not specifying each record to be updated,
just the criteria to let the DB engine choose them.  Also, the new
field content is either a constant or specified as a function of other
fields (when using F() objects); again, not specified individually,
but let to the DB engine to work it out.

in sum, it's a _lot_ less data to prepare, send, and interpret and
uses a heavily optimized, totally SQL statement.  Not having it would
be a big missing feature.

-- 
Javier

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