Hello, I belive that the document in the help file is pretty complete. Actually it was proof read by Yuki :-) (thanks!)
As I wrote you can not WRITE to FastTrack database. You can however switch back and forth from local <-> FT. I won't go into repeating what is in the guide, instead will give you just the procedure you may use: 1. Start of the day 2. Set "Data source" to "FastTrack". Run ANY AA scan (can be one liner: buy=0;) on all symbols (that will copy files to AB local db) 3. Switch "Data source" to "(local database)". Now you have write access, you can write your data to OI field. 4. End of the day - turn back to "FastTrack" (your changes to OpenInterest will be lost at that moment). Best regards, Tomasz Janeczko amibroker.com ----- Original Message ----- From: Ken Close To: [email protected] Sent: Tuesday, July 08, 2008 3:28 PM Subject: RE: [amibroker] More on Database Structure and Local Storage Hello Tomasz: Of course you are right, again, but the page in help/guide is still incomplete in order to impart a good understanding of how this all works. How does one use local database (say with FastTrack data) and still get nightly updates installed so everything works right? What does local database really mean as everyone has to get their data from some external source? I clicked on the DATA SOURCE (vs my previously just checking the Enable local storage button), and everything seemed the same. I could go between symbols in the tree, and things seemed to plot the same. There was no long disk activity suggesting that AB was writing data from the FT data files to the local AB data files. So how does that work? My critical question: Am I able to use FastTrack data, locally, and write custom values to OI that will be saved, AND STILL, somehow, update nightly FastTrack data? Can you say it is possible, and if so how are nightly updates accomplished? This is all critical to a custom application (as we have been discussing in other messages). Thanks for continuing to provide support on this issue. Ken ------------------------------------------------------------------------------ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Tomasz Janeczko Sent: Tuesday, July 08, 2008 8:12 AM To: [email protected] Subject: Re: [amibroker] More on Database Structure and Local Storage Hello, To switch to LOCAL database, you just go to File->Database Settings and change "Data SOURCE" to "(local database)". But that means that you are NOT using FastTrack as data source. You can *not* have both, i.e. using FastTrack as a data source and having database WRITE ability, because access to FastTrack database is READ ONLY. The only exceptions are COMPOSITES (and any symbol marked as "use local database only" in the Information window) - they are NOT present in external database and are always saved locally. It was explained in the docs I pointed previously: http://www.amibroker.com/guide/h_workspace.html Best regards, Tomasz Janeczko amibroker.com ----- Original Message ----- From: Ken Close To: [email protected] Sent: Tuesday, July 08, 2008 1:46 PM Subject: [amibroker] More on Database Structure and Local Storage Can someone explain to me how I make the FastTrack database a local one? Background: I have had a FT db for years, with local storage disabled? I want to write to the OI field and preserve the written data. I checked "Enable Local Storage" but nothing different happened. Next, I tried to scan all symbols with a simple formula (I remembered having to do that years ago with a TC2000 database that came on a CD--I thought the same kind of step was needed.). Amibroker got hung on a single symbol and I had to End Program. AB would lock if I even clicked on this same symbol. Next, I created a new FastTrack database with a different name and copied over the appropriate files to the new DB folder. I enabled Local Storage from the start. All looked good. Except that writes to the OI field in the new DB would not save. I tried the scan all symbols trick again, and again it hung on the same symbol, certainly suggesting my FastTrack data itself is corrupt on that one symbol. (Special updates with the FastTrack data designed to correct problems did not seem to change anything.) My question is how do I get the FastTrack database to be local and to allow writes to the OI field to stick? My second question (as I assume I have to have the data in the Amibroker folders and not just in the FastTrack folders for the AB DB to be local), is how do I update the nightly downloads of new data which FastTrack will stick in their own file/folder? Thomasz, can you help? Thanks, Ken
