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 [email protected], "Tomasz Janeczko" <[EMAIL PROTECTED]> 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" <[EMAIL PROTECTED]> > To: <[email protected]> > 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 > > > > > > > > > > >
