Some of you may have read a number of recent exchanges I made with others
about the speed of execution of a particular piece of code which did
"ordinal rankings". I complained that Watchlists with 450 or so symbols
were taking hours and Tomasz and Paul Ho wrote back and said that they were
experiencing execution times on the same code in the order of minutes.
After doing all sorts of things, and seeing no meaningful changes to the
execution times, I decided to experiment with my database source.
My only (current) database source is the FastTrack database. My database
settings are FastTrack database plugin, Local data storage: disabled, Number
of bars: 50000.
I have previous subscribed to QuotesPlus, and while I ended my subscription
in Oct of 2007, lazy me still had the database installed with the following
settings: QuotesPlus plugin; Local data storage: enabled; Number of bars:
100000 (ha, I get too zealous with the zero key).
A run with the same code, on approximately the same size Watchlist (452
members) showed Paul Ho's original code (single indicator) to complete in
about 45 seconds, while my modified code (two indicators) was on the way to
completion in about 22 minutes compared to the 1 hour 30 to 50 minutes I was
seeing with the FastTrack database.
So I am left to wonder whether the FastTrack plugin and its interface with
the FastTrack data is the reason the retrieval is so slow compared to the
QuotesPlus plugin. Or, whether the Local Storage enabled is the key factor.
Further, I suspect but am not sure that the number of bars I stick in the
box has little to do with the access times (in this case of EOD data) but I
am not sure.
I would like to hear the pros (faster times) and cons (wasted HD space??) of
having local storage enabled. Can some one share before I convert my
FastTrack data to local storage for a test.
Thanks for your advice.
Ken
