Hi!

I just realized, that I can speed up my application (connected to the DB
via a DSL-VPN) by changing the PREFETCHROWS to 100. What are good values
for this parameter and do I have to change the PREFETCHBUFFER parameter as
well? The ASA documentation is not very detailed in this section.

Claudius

PS: I'm using ASA 7

Claudius Schmid wrote:
The answer to this, as in most programming questions of this sort, is
"it depends". There are many variables involved:

- amount of memory available on the client
- speed of network
- amount of data to be transfered
- ways that your application uses the cursor
- etc...

If your configuration can handle it, then set the values quite high.
But if your application is using a cursor to fetch a small number of
rows, then looping through the cursor one at a time looking for those
rows is "expensive".

The best thing to do is to play around with the parameters and run your
test suite again (the one that uses 'real world' values under 'real
world' conditions).


I just read the 7.0 version of the docs:

ASA Adaptive Server Anywhere Reference Manual
CHAPTER 3. Connection and Communication Parameters
Connection parameters
- PrefetchBuffer connection parameter [PBUF]

and
- PrefetchRows connection parameter [PROWS]

In my opinion, they are quite accurate. There are no suggested values
because, as stated above, different applications may use radically
different values (e.g. a "music collection" application on a CE device
vs. a retail cash register system running on a multi-CPU GNU/Linux server).

If you have any suggestions on what information is missing or what parts
should be reworded, post your comments and we'll forward them to the
docs team.


Hope this helps,
greg.fenton
--
Greg Fenton
Consultant, Solution Services, iAnywhere Solutions
--------
Visit the iAnywhere Solutions Developer Community
Whitepapers, TechDocs, Downloads
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Greg Fenton <greg.fenton_NOSPAM_ (AT) ianywhere (DOT) com> wrote in
news:3fdab715@forums-2-dub:

It would be great to hear some technical details about these parameters to know
exactly what you're doing by changing the values. I think trying out is one way,
but that's not very scientific ;-)

Claudius

Claudius Schmid wrote:

How about this from the ASA 7.0.4 docs:

ASA Adaptive Server Anywhere User's Guide
PART 2. Working with Databases
CHAPTER 10. Using SQL in Applications
Working with cursors
- Prefetching rows

??

greg.fenton
--
Greg Fenton
Consultant, Solution Services, iAnywhere Solutions
--------
Visit the iAnywhere Solutions Developer Community
Whitepapers, TechDocs, Downloads
http://www.ianywhere.com/developer/