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Hello,
Why don't you move to Metastock that has 65000 bar limit ?
The truth is that AmiBroker is the most capable in this area because
it stores way more data than other softwares. Also, by changing the registry
limit you can set it to any value you need. The limit is not the software but the hardware
It is funny when people make statements like yours without taking calculator and
actually checking how much memory you need to store that.
20 million bars - OK, but did you actually count how much memory you need for that?
Each quote is 64 bytes, now 20 million of bars is 1.2GB of memory per symbol.
You may say "but you don't need to load it at once". But unfortunatelly you do need that.
How you can backtest without loading the data ?
And each AFL array in such case would need 4 * 20 million = 80 MB of RAM.
Usually user formulas use hundreds of such arrays.
Wise old words are: "You can't eat your cake and have it too".
If you want more data stored - the price for that is increased memory requirements
and more CPU power needed to process it.
Now you can say: you can process one bar at a time - yes you can - but you need
to store intermediate results anyway for next iteration and that means that memory requirements
would not be even one byte less than they are. Plus changing execution model to 1-bar at a time will
mean (number-of-bars)-times slow down.
So you would end up with system that is slow, slow and even more slow.
Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message -----
From: "scourt2000" <stevehite@xxxxxxxxxxx>
To: <amibroker@xxxxxxxxxxxxxxx>
Sent: Wednesday, September 12, 2007 2:00 PM
Subject: [amibroker] Re: Is 500,000 the maximum number of bars allowable in a database?
>
> And this is my biggest pet peeve about Amibroker:
>
> If I have the disk space available, Amibroker should never, ever, EVER
> just silently blow away my historical data because of some arbitrary
> system limit like 500,000 bars or 1,000,000. If I want 20 million
> bars historical and I have the disk space to store it, then fine. If
> Amibroker needs far less to function well, then that's fine too.
>
> The solution is NOT to delete old data. The solution is to have a way
> for Amibroker to limit the number of past bars (for calculation
> purposes) or even have me set a beginning and end date in an
> historical range WITHOUT destroying that historical data (i.e., the
> present day should not have to be the last bar that I view or use for
> backtesting).
>
> Currently, the only solution is to set some registry value to go over
> 500,000, but that in itself is not solution. Because of Amibroker's
> implementation, you'll get your memory stressed out big time and,
> again, if your new limit gets reached, Amibroker will remove your
> oldest data to make room for new data.
>
> No one ever said that you had to look at stock/futures data from the
> complete past to today. If I had 20 years of one symbol's data and
> that data was far too much to make available at one time because of
> memory problems, then it should be segmentable without me having to
> split of the data in artificial symbols.
>
> Of course there's a workaround (there usually is). You have to split
> your data up (e.g., tick data) into segments with different artificial
> symbol names (e.g., I use eSignal continuous futures contracts).
>
>
> --- In amibroker@xxxxxxxxxxxxxxx, Graham <kavemanperth@xxx> wrote:
>>
>> I believe the database limit is set to 500,000 but can be changed in
>> the windows registry. TJ has mentioned this in a previous post here,
>> somewhere sometime.
>>
>>
>> --
>> Cheers
>> Graham Kav
>> AFL Writing Service
>> http://www.aflwriting.com
>>
>>
>> On 12/09/2007, Ara Kaloustian <ara1@xxx> wrote:
>> >
>> >
>> > You can have as much as you want, but performance degrades.
>> >
>>
>
>
>
>
> 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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For other support material please check also:
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