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From: Robby P. <Rob...@nx...> - 2013-01-15 15:08:14
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Thx for the investigation. We indeed use the XQJ API. I guess I will need to check out the packaged Java API.
Robby
From: Konstantin Abakumov [mailto:rus...@gm...]
Sent: Tuesday, January 15, 2013 3:16 PM
To: Robby Pelssers
Cc: sed...@li...; Ivan Shcheklein; Oleg Borisenko
Subject: Re: [Sedna-discussion] poor performance for large collection
Hi again!
I suggest that you are using Sedna XQJ API, is it right?
I've compared three drivers on your queries:
1. Java API
, packaged with Sedna,
2. Sedna XML:DB API
3. Sedna XQJ API
, both from Charles Foster
It took only several seconds to execute queries using 1 and 2, but XQJ API worked about half a minute on each query - seems it can be a bottleneck in your case.
2013/1/15 Robby Pelssers <Rob...@nx...<mailto:Rob...@nx...>>
Hi,
We use the driver from Charles Foster. But also a test using the Sedna Database Administrator results in temporarily freezing. It is indeed a remote host.
Robby
From: Konstantin Abakumov [mailto:rus...@gm...<mailto:rus...@gm...>]
Sent: Tuesday, January 15, 2013 1:49 AM
To: Robby Pelssers
Cc: ???? ?????????; sed...@li...<mailto:sed...@li...>
Subject: Re: [Sedna-discussion] poor performance for large collection
Hello again!
Sorry for the late reply. And thank you for sending us the data!
Both the queries you had profiled in previous letters executed fast on my machine:
for $i in index-scan("chemicalcontent_id", "", "GE")/@id return string($i)
and
for $doc in collection("chemicalContent/released") return document-uri($doc)
it took less than a second to execute each of them. I had executed queries on locally through built-in terminal se_term.
You noticed that:
Serializing and sending that data over the wire… takes like forever.. >> 1 minute.
Seems that slowdown can be achieved during connection to Sedna and sending query results. Is Sedna server located on remote host? What driver do you use?
--
I've tried some tests on generated data. As expected, the more schema of individual documents differs from each other, the more performance degradation is observed. But in case of similar or not very different documents (which is yours) Sedna performs satisfactory fast. Hope that we will resolve your performance issue.
Best regards,
Konstantin Abakumov
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С уважением,
Константин Абакумов.
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