Hello Christian,
we have started working in this small project as I informed you. We have set up server/client problem and we have run many test queries on the standard Xmark database. I have some questions though. For example I run:
for $b in basex:db('standard')/site/open_auctions/open_auction return <increase>{$b/bidder[1]/increase/text()}</increase>
With options -z -r100 and I get:
Parsing: 0.15 ms (avg) Compiling: 2.49 ms (avg) Evaluating: 0.0 ms (avg) Printing: 140.66 ms (avg) Total Time: 143.31 ms (avg) Results: 12000 Items Printed: 69 Bytes Memory: 6354 KB
Do you think this output is normal? I do not understand why printing time is not 0 since I use '-z'. Should we include printing in timing our benchmarks?
In addition what exactly does OPTIMIZE? If we just create a DB based on an .xml file and we dont actually UPDATE anything but we only perform queries, then optimize does not change anything, right? I mean when created a DB is already 'optimized'?
I tried to find all this answers in documentation but I couldn't. Thanks for the help!
Best regards, Antonis
On 06/28/2010 01:34 AM, Christian Grün wrote:
Dear Antonis,
thanks for your e-mail and your interest to use BaseX for your class.
We have performed numerous comparisons with other XML databases by ourselves, but your results could include helpful hints as well, so your focus sounds fine to us. Keep in mind, however, that the given time frame is very tough, as long as you haven't done serious benchmarking before: you will most likely encounter side effects, which can lead to completely wrong interpretations of performance results.
As first hint, I'd recommend you to use the latest BaseX version and the client/server architecture for all tests, and the -v option to display the BaseX timing output:
$ java -Xmx1g -cp basex-6.1.7.jar org.basex.BaseXServer BaseX 6.1.7 [Server] Server was started.
$ java -cp basex-6.1.7.jar org.basex.BaseXClient -Uadmin -Padmin -v query.xq
<xml/> Parsing: 0.04 ms Compiling: 0.02 ms Evaluating: 0.01 ms Printing: 0.05 ms Total Time: 0.19 ms Results: 1 Item Printed: 42 Bytes Memory: 2180 KB
You might use the hidden "-r" option to increase the number of runs:
$ java -cp basex-6.1.7.jar org.basex.BaseXClient -Uadmin -Padmin -r100 -v query.xq
<xml/> Parsing: 0.02 ms (avg) Compiling: 0.0 ms (avg) Evaluating: 0.0 ms (avg) Printing: 0.02 ms (avg) Total Time: 0.04 ms (avg) Results: 1 Item Printed: 42 Bytes Memory: 2604 KB
You can also use BaseX commands:
$ java -cp basex-6.1.7.jar org.basex.BaseXClient -Uadmin -Padmin -c "set info on; set runs 100; run query.xq" …
Check out http://basex.org/server for details on using c/s. Next, the following post from Michael Kay on benchmarking is well worth reading:
http://x-query.com/pipermail/talk/2009-October/003613.html
Best, Christian
On Sun, Jun 27, 2010 at 4:06 PM, Antonis Thomas iorulezz@gmail.com wrote:
Hello all,
we are two master students at the university of Utrecht. We have a DB Architecture class that includes a small project (15%*7.5 ECTS= 1.125 ECTS). So, BaseX looks like a good chance to work on such a project.
Our idea so far is based on some benchmarking experiments and small summary on how it works (maybe its relation with Monet) including any experiments we run (5-6 pages). Do you have anything better for us to do (maybe something you can get advantage of yourselves) or any guidelines/hints/whatever?
Take into account that out time limit is approximately a week (full-time) and that we cannot do more work that what deserves 2.25ECTS for the 2 of us.
I look forward to an answer (so we can decide and start working -the deadline is 9/7-.
Best regards,
Antonis Thomas Information & Computing Sciences Utrecht University Utrecht, The Netherlands
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