performance vs. readability/maintability

[Daniel Billingsley]

In another online group in which I participate, we were discussing a
particular piece of code that had a pretty high risk for breaking in the
future (because it depended on something not changing that was outside the
developer's control) but was slightly more performant. One participant
posted:

"I tend to take the performance track also, adding readability if the impact
isn't too great. There is also an odd reality that takes place even in the
software field however. Not sure I can explain it too well but simply said,
if you write code to handle the effects of changing the ordinal position of
a field, some other error will surface anyway."

which I found to be ridiculous to the point of being dangerous.

I know this is somewhat one of those opinion issues, but I just wondered
where everyone fell on the continuum.

[Daniel Billingsley]

Yeah the quote I posted actually makes two points

1) readability vs. performance
2) reliability vs. performance

with the author says he chooses performance in both cases.

My basic position tends to be that in most cases the performance differences
we're talking about our trivial (the tests used to demonstrate them often
use 10,000,000 iterations and our code is doing exactly one per hour, for
example). I can't see any wisdom whatsoever in obsessing over such trivial
performance gains and sacrificing what may well be hours of future work on
the code.

As far as the reliability, I think the position of writing code that is
pretty likely to break some day because it performs slightly better is just
ludicrous. In this particular case, it was in the context of database
access, which I think will far overshadow any milliseconds saved here or
there by writing theoretically perfect code.

"J.Marsch" <je****@ctcdeve loper.com> wrote in message
news:ek******** *****@tk2msftng p13.phx.gbl...

For what it's worth I would almost always side with reliability. I hate
fixing code, especially when it's due to a bad decision on my behalf. I
suppose that if I were in a situation where some code absolutely had to run faster (show-stopper), and the modification was the only way to get over the line, and the reliability problem was not random, but a maintenance issue,
(only a bug if the table structure changes), and the reliability problem
would not cause more damage than running too slow..

Then maybe I would bring it up in a meeting, just so that my coworkers could talk me out of it.

Regards