Hi, I grab the quotations from IB.
Regularly datas disappear from my Index symbol. I made mistakes before to understand how database settings are important. My setting was 100000 and every year I have lost datas when the database has reached the maximum . My index receives a quotation every 30 seconds. My minimum time unit is 1 minute. I get about 510 " 1' bar " per day, per month : 510 x 20 = 10200 per year : 10200 x 12 = 122400 I want to keep my Index's whole history. I read that the default max is 500 000. Does it mean that my index can't be more than 4 years ? This point is confirmed by TJ's post specifiing the following... ( An answer to Joseph Biran, Sidartha, about database size ). >> This key is a "hidden extra feature" for advanced users having >>computers powerful enough to handle extra load. >>By default the key does not exist and then the default max is >>500000. >>Tomasz Janeczko My Pentium IV is not powerful. I'd like to fully understand the involvements before to shift to i7 family and S7. TJ's comment is in tune with AB warning "increasing this value can degrade the performance". The load factor is higher. I set 200000 an the load factor is 97%. I set 100000 an the load factor is 57%. The load factor is higher with the same number of bars, I supposed that more RAM is reserved. So the ratio is worst. The point that drives me crazy, I use mainly the Index in daily or weekly, sometimes in hourly, so I do not need to keep it in 1'. EOD is not enough, hourly at least. I don't understand the best way to keep the datas concerning the Index. Should I build, at the end of every day, an hourly and daily and weekly handmade symbol into four separated time unit ? It'a a bit heavy to manipulate. Actually I kept backups but the AB format changing with EUR at the end after v:5.27 does not allow to merge and recover my backups. No way to open them into Excel and to re-inject into AB. The second major point is that this general max bars database setting is common to future contracts and Index (and stocks, I don't use). Future needs about 50000 for a quarterly contract. My future contracts are montly, it's roughly 35000 bars in 1' for two months of quotations. I can't imagine the constraints for people that store a thousand of stocks datas and Indexes, grabbed in 1' and used in hourly and daily for analyse. Any help appreciated to keep Index history as long as possible without destroying the load factor, and if somebody knows how to extract backup datas and recover them from old version ? Best regards
