D'Arcy J.M. Cain wrote:
I keep seeing this statement but nothing to back it up. I have created many apps that run on Python with a PostgreSQL database with a fully normalized schema and I can assure you that database joins were never my problem unless I made a badly constructed query or left off a critical index.
I too have done that (Python/PGSQL), even adding a complicated layer of SQLAlchemy on top of it and have not had issue with this: when I profiled one of my apps, it turned out that it spent most of its computation time... rendering HTML. Completely unexpected: I expected DB to be bottleneck (although it might be that with huge datasets this might change).
Having said that, re evidence that joins are bad: from what I've *heard* about Hibernate in Java from people who used it (I haven't used Hibernate apart from "hello world"), in case of complicated object hierarchies it supposedly generates a lot of JOINs and that supposedly kills DB performance.
So there *may* be some evidence that joins are indeed bad in practice. If someone has smth specific/interesting on the subject, please post.
Regards, mk -- http://mail.python.org/mailman/listinfo/python-list
