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Showing posts from November, 2005

A point for ORM developers to remember

If you are writing an ORM tool, please keep this one point in mind: I already know SQL. Your new query syntax isn't better; it's just different. Which means one more thing for me to learn. Which means I probably won't bother, and will use instead an ORM tool that respects my time. Consider: if your target audience is like me, and already knows SQL, this should go without saying. Resist the temptation to be "clever" and overcomplicate things. If your target audience does not know SQL, then either they intend to learn SQL, because they're using a relational database and expect that non-python code or ad-hoc queries will be necessary at some point, or they have no intention of learning SQL, and all their data-access code will now and forever be in python, in which case they would be better off using Durus or ZODB or another OODB. Be honest with these people and everyone will be happier. Django does some cool stuff, but heaven help me if I ever had...

PATA really, really sucks

Trying to figure out why sometimes disk access on my test machine takes way, way too long -- 1000+ ms -- I wrote some test code. My threads ran a function that looks like this: write = [] def writer(): while True: start = time.time() f = tempfile.TemporaryFile() f.write('a' * 4000) end = time.time() write.append(end - start) Compare the times for max(write) on a machine with a SATA disk and on one with parallel ATA, where the given number of threads are run for a 10 second period: threads pata sata 1 6ms 6ms 2 400ms 11ms 4 1300ms 24ms Ouch. I admit I'm not a hardware nerd. Quite possibly I'm missing something, because even PATA shouldn't be THAT bad. Right? hdparm -i says for the PATA disk: /dev/hda: Model=ST380011A, FwRev=8.01, SerialNo=4JV59KZT Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% } RawCHS=16383/16/63,...