Lawrence D'Oliveiro wrote: > In message <mailman.2504.1257216390.2807.python-l...@python.org>, Carsten > Haese wrote: > >> With all due respect, but if your experience is exclusive to >> MySQL/MySQLdb, your experience means very little for database >> programming practices in general. > > I wonder about the veracity of your claims, because: > >> And here are the corresponding results on my laptop: >> $ python -mtimeit -s "from querytest import Tester; t=Tester()" >> 't.with_params()' >> 10000 loops, best of 3: 20.9 usec per loop >> $ python -mtimeit -s "from querytest import Tester; t=Tester()" >> 't.without_params()' >> 10000 loops, best of 3: 36.2 usec per loop > > Didn't you say previously that there should be a "seven orders of magnitude" > difference? What happened to that claim?
"That claim" was an exaggeration I resorted to after you distorted the concept of choosing the right tool for the job into premature optimization. It wasn't my initial claim. The "seven orders" (which is actually log-10 orders of however often the same query is executed with different values) is of course only the cost increase on parsing the query itself, which as you pointed out is drowned out by other fixed costs associated with performing database queries. However, you can't dispute the fact that using string interpolation *is* in general less efficient than parameter binding, and that was my initial claim. -- Carsten Haese http://informixdb.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
