Re: [Exist-open] xquery performence

[Wolfgang M. <wol...@ex...>]

Hi,

If you look at eXist's log output, you will find that compiling the query=20
takes much longer than executing the query. Using client.sh -ls, compilatio=
n=20
takes 900ms, query execution takes 140ms. Subsequent queries will be much=20
faster (59ms to compile, 5ms for query execution). The database has to fill=
=20
its page buffers, so it needs some time to initialize itself.

The strange thing is, however, that the first call to the XQuery compiler o=
n a=20
freshly initialized database is a magnitude slower than later calls. I can'=
t=20
explain this, but I suspect that the delay is caused by the Java classloade=
r=20
(the XQueryContext uses introspection to load XQuery modules).

If you still see performance problems, send me your data set and I will try=
 to=20
figure out what's wrong.

Wolfgang

On Saturday 17 April 2004 10:54, Yusuf U=F0ur Soysal wrote:
> hi,
>
> I've read the xquery performence topics in the email
> archive, but I couldn't be sure that my queries run at
> normal speed.
>
> Here is the query:
> xquery version "1.0";
>
> for $player at $i in
> collection('db/graduation/players')/nba/player
> 	let $season :=3D
> $player/career/pSeason[position()=3Dlast()]
> 	let $val    :=3D $season/assist/text()
> 	where $i <=3D 30
> 	order by $val descending
> 	return <player>
> 				{$player/plyrName}
> 				{$player/id}
> 				<team>{$player/playingAt/text()}</team>
> 				{$season/game}
> 				<val>{$val}</val>
> 			</player>
>
> And the xml file, that I'm queriying is at the bottom
> of the email. This queries took about 1.5 - 2 seconds
> and there are 408 xml files in the collection. Is the
> speed is normal? It seems a little slow to me.
>
> An example of the xml file:
> <?xml version=3D"1.0" encoding=3D"UTF-8"?>
> <nba
> xmlns:xsi=3D"http://www.w3.org/2001/XMLSchema-instance"
> xsi:noNamespaceSchemaLocation=3D"xsd/nba.xsd">
>     <player>
>         <id>2</id>
>         <plyrName>Boris Diaw</plyrName>
>         <dateOfBirth>16/4/82</dateOfBirth>
>         <height>6-8</height>
>         <weight>215</weight>
>         <position>G</position>
>         <playingAt link=3D"1">Atlanta Hawks</playingAt>
>         <highScores>
>             <point>0</point>
>             <minute>0</minute>
>             <fieldGoal>
>                 <made>0</made>
>                 <attempted>0</attempted>
>             </fieldGoal>
>             <threePoint>
>                 <made>0</made>
>                 <attempted>0</attempted>
>             </threePoint>
>             <freeThrow>
>                 <made>0</made>
>                 <attempted>0</attempted>
>             </freeThrow>
>             <hRebound>
>                 <offensive>0</offensive>
>                 <defensive>0</defensive>
>                 <total>0</total>
>             </hRebound>
>             <assist>0</assist>
>             <steal>0</steal>
>             <block>0</block>
>         </highScores>
>         <career>
>             <pSeason year=3D"03-04">
>                 <teamName link=3D"1">Atlanta
> Hawks</teamName>
>                 <game>0</game>
>                 <point>0</point>
>                 <minute>0</minute>
>                 <fieldGoal>
>                     <made>0</made>
>                     <attempted>0</attempted>
>                 </fieldGoal>
>                 <threePoint>
>                     <made>0</made>
>                     <attempted>0</attempted>
>                 </threePoint>
>                 <freeThrow>
>                     <made>0</made>
>                     <attempted>0</attempted>
>                 </freeThrow>
>                 <pRebound>
>                     <offensive>0</offensive>
>                     <defensive>0</defensive>
>                 </pRebound>
>                 <assist>0</assist>
>                 <steal>0</steal>
>                 <block>0</block>
>                 <turnover>0</turnover>
>                 <personalFoul>0</personalFoul>
>             </pSeason>
>         </career>
>     </player>
> </nba>
>
>
> =3D=3D=3D=3D=3D
> http://students.sabanciuniv.edu/~ocelep/shadow/