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If 8-10 min. is to be expected, then that's OK. I'm just wanting to
make sure that I have everything setup correctly in AB, because for
that 8-10 min. my hard drive is working pretty hard to keep up.
As for the "second scans," I have written some relatively complex
scans for StockFetcher that finished in a matter of seconds, so I'm
wondering how StockFetcher runs "hard coded" scans on my custom code.
Anyway, no problem.
Thanks Tomasz
--- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <groups@xxx> wrote:
>
> Hello,
>
> That's funny. People misled by advertising start repeating all what
they heard on the ad.
>
> So for your information: web pages and other "services" offering
"second scans"
> give you a bunch of "hard coded" / precomputed scans - they run a
dozen of scans on their
> servers periodically and what you see is NOT result of actual scan being
> performed in real time but just the display of somethign that was
prepared earlier
> and stored in the file. Or they display a query over database with
some fixed
> indexed field (like % change or something) - the same. What they
offer is all hard coded / precalculated.
>
> Now if you want to run REAL scan using CUSTOM formula you need to
actually
> EXECUTE this on the data.
>
> Now to these 8 minutes for entire US database - it is relatively
fast. It would be much faster if you
> used NATIVE AmiBroker database, not external one, as AmiBroker
mostly waits
> for data from external source. The same scan using native database
with enough
> ram should take about one minute.
> If you for example have 15000 symbols and each has 2600 quotes and
say that your scan involves
> only single MACD to calculate it you need to access 39 million
quotes (2496 megabytes) and perform 78 million multiplications
> and additions. Computation is not really a problem but reading the
data (2.5 GB) is actually quite a task.
> Try just COPYING 2.5GB of data (take such a file and copy it) and
you will see it takes one minute.
> So AmiBroker using NATIVE database runs with speed of hard disk
copy. Which means that actual
> processing takes almost nothing.
>
> And this is actually best speed you will get from any software (of
course considering
> only softwares that perform actual computations, not merely display
pre-computed files stored on disk).
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
> ----- Original Message -----
> From: "Gerald Monks" <glmonks@xxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Monday, July 23, 2007 6:26 PM
> Subject: [amibroker] Explorations/Scans are really slow...
>
>
> > It takes between 8-10 minutes to complete an exploration (a simple one
> > at that) of all US stocks. My EOD database is from Quotes Plus. Is
> > this normal? For example, a comparatively complex scan of all US
> > stocks with StockFetcher (over the internet of course) only takes
> > around 4-5 seconds.
> >
> > Do I have a wrong setting somewhere in AB?
> >
> > Thanks
> >
> >
> >
> >
> > Please note that this group is for discussion between users only.
> >
> > To get support from AmiBroker please send an e-mail directly to
> > SUPPORT {at} amibroker.com
> >
> > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
> > http://www.amibroker.com/devlog/
> >
> > For other support material please check also:
> > http://www.amibroker.com/support.html
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>
Please note that this group is for discussion between users only.
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SUPPORT {at} amibroker.com
For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
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