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On 20-Jan-99, Mortillaro Rosario wrote:
> As the Data Base continues to grow gibber and bigger every day,
> is it possible to do the following ?
To clarify, Mortillaro tracks all stocks on his local exchange; that is why
his database grows. New stocks get added whenever they appear in his
information source; retired tickers can't be removed easily (smartly), with
an automatic program.
> Every now and then have a script AREXX to check the share/tickers not
> updated within a certain period of time, with a share list ?
> After I can control the list and delete what is not interesting for me?
Saro:
I found a few problems with doing this automatically, with a program. Why?
A ticker may not be used (or is just inactive) for a number of reasons: the
company changed its name or the co. got acquired (Chrysler disappeared
when Daimler-Benz merged with it); the stock could have been delisted or
suspended for not keeping up with exchange requirements. There are other
reasons that a ticker may stop trading, such as the ticker was temporary,
anyway, for warrants or installment receipts, etc. For whatever the reason,
you may want to still keep the information around - maybe the ticker will
continue to be used, later. You just don't know, with some of these.
Since many of your histories are short, you might not want to get rid of this
valuable information too quickly. Instead of deleting them right away, why
not move them to another drawer for a while, *then* delete them later?
(Move the files when AmiBroker is not running.)
What I did was write a program to export certain info, enough to check
which tickers are inactive. Then I look each one up individually, to see
whether I wish to merge the data with another ticker, keep or delete it. The
early price information for a when-issued stock is especially useful. This
is why *everyone* needs my history exporter program!
I did this recently, at the 1998 year end. I made a few mistakes, until I
learned how to recognise a dead stock better, but it went OK. It pared
my database down to almost the exact size of my information source. ;^)
I hope that helps you,
---===///||| Donald Dalley |||\\\===---
The World of AmiBroker Support
http://webhome.idirect.com/~ddalley
Member: ICOA and Team AMIGA
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