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Posted by Markus Ernst on 11/10/06 10:34
Jerry Stuckle schrieb:
> Markus Ernst wrote:
>> Jerry Stuckle schrieb:
[...]
>>> The real question is - are you actually having performance problems,
>>> or are you spinning your wheels on something which may or may not be
>>> a problem? I suspect the latter.
>>
>>
>> Your suspection is correct. After I _had_ performance problems (30+
>> seconds execution time for displaying 20 or 30 items...) I started
>> caring for performance issues at all, and now I try to be aware of
>> them even before problems occur. With my poor technical background (I
>> don't have a basic IT education) this sometimes makes me spend too
>> much effort on questions of low priority. Thus, comments of the kind
>> you posted are very helpful for me, thanks!
>
> I understand. I've been programming since the late 60's, and have seen
> my share of performance problems (think of what it was like to be on a
> mainframe with 4,000 bytes - not 4K - of core memory, running at
> something quite a bit less than 1Mhz clock rate).
>
> And yes, you should always keep potential performance problems in mind
> when programming. But I really don't worry about them until I get the
> first cut at the program running and see if I have performance problems.
>
> As an example - I wrote a fairly small C++ program with a lot of
> recursive calculations (the theoretical max was 81! (81 factorial - 81 x
> 80 x 79 ... x 3 x 2 x 1) operations. The goal was to have it finish the
> ops in something less than a couple of minutes on a 900Mhz laptop.
>
> I went ahead and wrote it, not paying much attention to performance.
> Results when I was done was every run was < 1 second. Mission
> accomplished.
>
> Another case I had to parse out a rather large (5MB) html file in PHP.
> The goal was to convert some huge tables to csv files for importing to a
> spreadsheet. The first run took over 15 minutes. So at that time I
> went back and optimized the code. Final results were around 20 seconds.
>
> The bottom line was - I didn't waste any time on the first one because
> it was already fast enough. The second one took me around 10% more time
> to tweak and get the speed down. But that was much easier because I
> already had the program working, and my design allowed me to easily
> modify the code to close up the bottlenecks.
I actually started learning Java now - not because I am sure I will
write Java in the future, but because I hope that knowing a less
permissive, strictly typed, purely object oriented, compiled language
will help me write better PHP :-)
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