Efficiently updating database using SQLAlchemy ORM

Question

I\'m starting a new application and looking at using an ORM -- in particular, SQLAlchemy.

Say I\'ve got a column \'foo\' in my database and I want to increment it.

Answer 1

Withough testing, I'd try:

for c in session.query(Stuff).all():
     c.foo = c.foo+1
session.commit()

(IIRC, commit() works without flush()).

I've found that at times doing a large query and then iterating in python can be up to 2 orders of magnitude faster than lots of queries. I assume that iterating over the query object is less efficient than iterating over a list generated by the all() method of the query object.

[Please note comment below - this did not speed things up at all].