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On Fri, 14 May 2004 21:53:59 -0700 (PDT), you wrote:
>
> From: "Abhijit Dey" <omegalist@xxxxxxxxxx>
> Date: Fri, 14 May 2004 15:22:57 -0500
>
> 2) Speed - all these tools get data from yahoo or somewhere else via http
> requests. 7000 http requests, no matter how you cut it takes a lot of time.
> If you get just a file per exchange, you can get your download done in <1
> minute vs. something potentially a lot more. Now only hope eoddata.com
> doesn't go away 8 )
>
>Because HTTP is a stateless protocol, you can massively parallize the
>fetches and gain an order of magnitude in speed.
Sven I fully agree with you on that but there are few things to say about it.
Setting up the the transfer takes a fair amout of time.
For ease of explanation lets assume 1 sec to setup and 1 sec to transfer 1 price
If you downloaded history worth of 7000 days that would take 1+7000=7001 seconds
Abhijit downloads 1 day with 7000 prices. Same speed. (but more manual actions)
But normally you don't need 10 year of data. Often only 1 day.
Then Abhijit's method takes 1+7000=7001 seconds.
Other downloaders take 7000*(1+1)=14000 seconds.
Things get more favourble for 'other downloaders' if the amount of day rises.
And they 100% automatic. Abhijit needs to download the files manually. (???)
Then we have the problem of splits. Redownloading historical quotes gives you
data with all splits done. Abhijit, how are you handling that?
I even know a program that currently detect splits and in the near future also
corrects the data if it detects a split when downloading just 1 day.
I think it's safe to assume everyone hates data with bad splits.
Multithreaded downloads will increase speed by a fair deal.
Fully automatic and the peace of mind that there are no splits that f*ck up my
systems/indicators is worth a fair amount of time for me.
5 seconds or 5 hours. No real diffrence if you are sleeping.
The huge advantage, imo, of Abhijit's system is that he can put the data in GS.
Does someone knows a MetaStock -> GS converter?
And a program that mimics MetaStock datafiles while in realitic it just fetches
GS data.
Global server is nice but a massive amount of (freeware) tools support MetaStock
data.
Tony
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