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Hello,
A very first update of Quotes Plus database may take long,
due to the fact that CD has older data and it must catch up until the most recent
day. Subsequent daily updates of all US stocks, mutual funds and future contracts take few minutes
(upto half an hour on slow internet connection).
The whole download and update process is however handled by Quotes Plus
software and I can not do anything about it. Please check http://www.egroups.com/messages/quotes-plus
for QP2 mailing list for more information about QP2.
As to AmiBroker itself - using QP2 plugin (description in the tutorial)
you can access all data in the QP2 database instantly.
Scans and explorations may seem a little bit slower than using local native AmiBroker database
but please consider that if you choose all options
you will track more than 50000 symbols and 10+ years history - this is quite a bit of data.
As for performance tweaking see the following excerpt from the tutorial:
"Plug in performance notes
Using AmiBroker native database gives absolutely the best performance (it takes less than 2 milliseconds to retrieve 1000 data
bars).
Metastock plugin is also quite fast, as it can retireve 1000 bars in about 6-7 milliseconds (including looking up for symbol in 5
different directories). In fact AmiBroker can access Metastock data faster than Metastock itself :-)
Quotes Plus performance depends on various factors - first access can be much slower (0.1-0.2 sec for 1000 bars) but subsequent
accesses are faster (downto 5 milliseconds).
TC2000 is not as fast, especially if you are using data only on CD. So it is advised to copy your database to hard disk for better
performance. But still, even when using CD-only data, AmiBroker ca access 1000 bars from TC2000 in about 0.25 sec (first access) and
0.015 sec (subsequent accesses). Also it is advised to enable "Local data storage" when using TC2000 plugin because it gives
tremendous (>10 times) speed-up (once you access the TC2000 data, AmiBroker caches them in its own native database for fast
retrieval).
Times are approximate and do not include one-time plug-in initialization process. Measurements where done on fairly low-end Celeron
600 based computer with 196KB RAM and 24x CD-ROM
In-memory caching
By default AmiBroker holds only 10 the most recently accessed stocks' data in RAM. This takes up about 320 KB (yes, kilobytes) of
memory for 1000 bars per stock loaded. You can enlarge "In memory cache" (Tools->Preferences : "Data" tab) to 100 (approx. 3.2MB
additional RAM consumption ) or 1000 (approx. 32MB additional RAM consumption) or even more to get much better performance for
subsequent data access (once data are in RAM AmiBroker does not need to ask plugin again and again)
"
Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message -----
From: "miked33" <miked@xxxx>
To: <amibroker@xxxxxxxxxxxxxxx>
Sent: Thursday, July 18, 2002 10:16 PM
Subject: [amibroker] Quotes Plus Problems
> I have just switched from Yahoo to Quotes Plus for data. I am
> downloading Stocks and Indexes. Is this what others are downloading?
> This is over 5000 stocks and is taking forever to do a 1 day update.
> Matter of fact sometimes in runs forever and I F12 it. It also
> appears to have slowed Amibroker down quite a bit. What are others
> downloading and is their a way to optimize the database?
>
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
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