Subject: RE: Optimizing a XSLT
From: "Michael Kay" <mhk@xxxxxxxxx>
Date: Tue, 15 Apr 2003 00:05:13 +0100
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Everyone looking at your code is immediately struck by the horrible use
of disable-output-escaping to write tags. But that's distracting people
from the real problem, which is:
<xsl:when test="unit=preceding::unit">
> <xsl:choose>
> <xsl:when test="schedule=preceding::schedule">
The preceding axis is very expensive, it has O(n^2) performance because
it searches the entire document up to the context node. I don't have
time to study your problem and suggest anything better, but the answer
is usually one or more of:
* use preceding-sibling
* use preceding::x[1]
* use keys
Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx
> -----Original Message-----
> From: owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Eric Barre
> Sent: 14 April 2003 19:02
> To: XSL-List@xxxxxxxxxxxxxxxxxxxxxx
> Cc: Eric Barre
> Subject: Optimizing a XSLT
>
>
> Hi,
>
> I wrote a XSL file to transform a XML file to another XML
> file, everything works fine on small file but eventually I
> will be using it against large XML file (over 1mg). When I
> run it against such a large file it takes for ever to return,
> I mean I have to kill it after running for an hour. Is there
> a way to optimize the XSL that I have to make it perform
> better? Here is the 'input' XML:
> <CSVFile>
> <ROW>
> <unit>DOUG_1</unit>
> <schedule>101</schedule>
> <textdate>2003-04-09</textdate>
> <texthour>18</texthour>
> <mw>999999</mw>
> <price>16.09</price>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </ROW>
> <ROW>
> <unit>DOUG_1</unit>
> <schedule>199</schedule>
> <textdate>2003-04-09</textdate>
> <texthour>18</texthour>
> <mw>999999</mw>
> <price>0.00</price>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </ROW>
> <ROW>
> <unit>ERIC_1</unit>
> <schedule>201</schedule>
> <textdate>2003-04-09</textdate>
> <texthour>18</texthour>
> <mw>0</mw>
> <price>10.79</price>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </ROW>
> <ROW>
> <unit>ERIC_1</unit>
> <schedule>201</schedule>
> <textdate>2003-04-09</textdate>
> <texthour>18</texthour>
> <mw>18</mw>
> <price>21.59</price>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </ROW>
> </CSVFile>
>
> The XSL:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <xsl:stylesheet version="1.0"
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
> <xsl:output method="xml" indent="no"/>
> <xsl:template match="/">
> <SubmitRequest>
> <xsl:call-template name="RowProcess"/>
> <xsl:text
> disable-output-escaping="yes"></PriceCurvehourly></xsl:text>
> <xsl:text
> disable-output-escaping="yes"></OfferPriceCurve></xsl:text>
> <xsl:text
> disable-output-escaping="yes"><ScheduleType></xsl:text>
> <xsl:value-of select="CSVFile/ROW/ScheduleType"/>
> <xsl:text
> disable-output-escaping="yes"></ScheduleType></xsl:text>
> <xsl:text
> disable-output-escaping="yes"><MarketAvailability></xsl:text>
> <xsl:value-of select="CSVFile/ROW/MarketAvailability"/>
> <xsl:text
> disable-output-escaping="yes"></MarketAvailability></xsl:text>
>
> <xsl:text
> disable-output-escaping="yes"></UnitScheduleOffer></xsl:text>
> </SubmitRequest>
> </xsl:template>
> <!--Processing-->
> <xsl:template name="RowProcess">
> <xsl:for-each select="/CSVFile/ROW">
> <xsl:call-template name="UnitProcess"/>
> </xsl:for-each>
> </xsl:template>
> <xsl:template name="UnitProcess">
> <xsl:call-template name="unit"/>
> </xsl:template>
> <xsl:template name="unit">
> <xsl:choose>
> <xsl:when test="unit=preceding::unit">
> <xsl:choose>
> <xsl:when test="schedule=preceding::schedule">
> <xsl:call-template name="PricePointProcess"/>
> </xsl:when>
> <xsl:otherwise>
> <xsl:call-template name="NewUnit"/>
> <xsl:call-template name="PricePointProcess"/>
> </xsl:otherwise>
> </xsl:choose>
> </xsl:when>
> <xsl:otherwise>
> <xsl:call-template name="NewUnit"/>
> <xsl:call-template name="PricePointProcess"/>
> </xsl:otherwise>
> </xsl:choose>
> </xsl:template>
> <xsl:template name="NewUnit">
> <xsl:choose>
> <xsl:when test="position()!=1">
> <xsl:text
> disable-output-escaping="yes"></PriceCurvehourly></xsl:text>
> <xsl:text
> disable-output-escaping="yes"></OfferPriceCurve></xsl:text>
> <xsl:text
> disable-output-escaping="yes"><ScheduleType></xsl:text>
> <xsl:value-of select="ScheduleType"/>
> <xsl:text
> disable-output-escaping="yes"></ScheduleType></xsl:text>
> <xsl:text
> disable-output-escaping="yes"><MarketAvailability></xsl:text>
> <xsl:value-of select="MarketAvailability"/>
> <xsl:text
> disable-output-escaping="yes"></MarketAvailability></xsl:text>
>
> <xsl:text
> disable-output-escaping="yes"></UnitScheduleOffer></xsl:
> text>
> </xsl:when>
> </xsl:choose>
> <xsl:text disable-output-escaping="yes"><UnitScheduleOffer
> unit="</xsl:text>
> <xsl:value-of select="unit"/>
> <xsl:text disable-output-escaping="yes">" schedule="</xsl:text>
> <xsl:value-of select="schedule"/>
> <xsl:text disable-output-escaping="yes">" day="</xsl:text>
> <xsl:value-of select="textdate"/>
> <xsl:text disable-output-escaping="yes">"></xsl:text>
> <xsl:text
> disable-output-escaping="yes"><OfferPriceCurve></xsl:text>
> <xsl:text disable-output-escaping="yes"><PriceCurvehourly
> hour="</xsl:text>
> <xsl:value-of select="texthour"/>
> <xsl:text disable-output-escaping="yes">"></xsl:text>
> </xsl:template>
> <xsl:template name="PricePointProcess">
> <xsl:text disable-output-escaping="yes"><PricePoint
> MW="</xsl:text>
> <xsl:value-of select="mw"/>
> <xsl:text disable-output-escaping="yes">" price="</xsl:text>
> <xsl:value-of select="price"/>
> <xsl:text disable-output-escaping="yes">"/></xsl:text>
> </xsl:template>
> </xsl:stylesheet>
>
>
> and the expected output:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <SubmitRequest>
> <UnitScheduleOffer unit="DOUG_1" schedule="101" day="2003-04-09">
> <OfferPriceCurve>
> <PriceCurvehourly hour="18">
> <PricePoint MW="0" price="8.04"/>
> <PricePoint MW="68" price="16.09"/>
> <PricePoint MW="999999" price="16.09"/>
> </PriceCurvehourly>
> </OfferPriceCurve>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </UnitScheduleOffer>
> <UnitScheduleOffer unit="DOUG_1" schedule="199" day="2003-04-09">
> <OfferPriceCurve>
> <PriceCurvehourly hour="18">
> <PricePoint MW="999999" price="0.00"/>
> </PriceCurvehourly>
> </OfferPriceCurve>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </UnitScheduleOffer>
> <UnitScheduleOffer unit="ERIC_1" schedule="201" day="2003-04-09">
> <OfferPriceCurve>
> <PriceCurvehourly hour="18">
> <PricePoint MW="0" price="10.79"/>
> <PricePoint MW="18" price="21.59"/>
> <PricePoint MW="999999" price="21.59"/>
> </PriceCurvehourly>
> </OfferPriceCurve>
> <ScheduleType>Cost</ScheduleType>
> <MarketAvailability>RealTime</MarketAvailability>
> </UnitScheduleOffer>
> </SubmitRequest>
>
> After reading some posting I tried to stay away from the
> <xsl:for-each> as much as possible as well as using variables
> and parameters. If anyone could let me know a way to optimize
> this I would appreciate it.
>
>
> Thanks,
> Eric Barre
>
>
> XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
>
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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