sidhartha70>>>So as a DB management strategy, it's best to perhaps have a large DB for backtesting purposes only... and a much smaller DB for live trading, charting, symbol swithcing etc..etc...?? ------------------------------------------------------------------------------------------ I think I remember that SET BARS REQUIRED will "NOT" stop Amibroker from looking back through the last 30 years even though I am looking at only the last day.
I would sure like a feature in Amibroker that would make SET BARS REQUIRED lookback only 101 days when the indicator looks back only 100 days. My backtesting days officially ended a few days ago. My backtesting consisted of viewing my indicator buy signals against 30 years of historical data. Even though I no longer backtest, I would still like to have a 30 year database, and here is why. Those symbols that are less volatile tend to have a decent amount of pattern similarity in my indicators as they enter into a NEW uptrend, after having been on a long term DOWNTREND. If I keep my 30 year database, then when I get a BUY signal, I can look back at the beginning of the previous new uptrends that occurred over the last 30 years. This lookback helps me decide how good the signal is. Ron D ----- Original Message ----- From: "sidhartha70" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, August 21, 2008 8:59 AM Subject: [amibroker] Re: Size of Database... > Thanks TJ. > > So as a DB management strategy, it's best to perhaps have a large DB > for backtesting purposes only... and a much smaller DB for live > trading, charting, symbol swithcing etc..etc...?? > > Thanks > > --- In [email protected], "Tomasz Janeczko" <[EMAIL PROTECTED]> wrote: >> >> Using 10x more data per symbol will give you slow down in all areas. >> 2 million bars is 64 MB per symbol of quote data and 8 MB per single > AFL array >> (if quickafl is not used). As formulas depending on complexity can > use hundreds of arrays >> this means approaching gigabytes of RAM. >> Handling that much of data is not "easy". Remember than RAM bandwidth >> is limited to few GB per second. Therefore just accessing that amount >> of data is question of seconds, not counting the calculations. >> >> Best regards, >> Tomasz Janeczko >> amibroker.com >> ----- Original Message ----- >> From: "sidhartha70" <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Thursday, August 21, 2008 2:48 PM >> Subject: [amibroker] Re: Size of Database... >> >> >> > Anyone...? >> > >> > Many Thanks >> > >> > --- In [email protected], "sidhartha70" <sidhartha70@> wrote: >> >> >> >> This may have been answered before, but... >> >> >> >> I set up two DB's in AB... both IQ Feed tick DB's. >> >> >> >> 1. Is 200,000 bars per symbol. >> >> 2. The second is 2,000,000 per symbol. >> >> >> >> Practially, operationally, where will AB be slower in the use of the >> >> second DB...?? In charting? Backtesting (obviosuly)? In symbol >> >> switching etc...? >> >> >> >> I'm just trying to work out how motivated I should be to have small >> >> DB's... >> >> >> >> 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. > > 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 > > >
