I don't know about performance, but in my opinion Version 1 is a better
design for the XML.  It provides a clear relationship between the key (IE)
and the value (Ireland), as they are both contained in the same element
(csl:value).  But in Version 2 the key and the value are in different
elements that are related by an implicit rule that needs to be explained,
namely that the value is in the first csl:value element following the
csl:key element that holds the key.  You'll find that the XPath to relate
keys to values will be simpler for Version 1 than for Version 2; this may
have some minor effect on performance.  In addition, and equally important
in my view, the average XSL programmer (if such a thing exists yet) would
probably work out the correct XPath for Version 1 by the second try, but
would have more difficulty with Version 2.

PC2

-----Original Message-----
From: James Pasley [mailto:James.Pasley@xxxxxxxxxxxxx]
Sent: July 27, 2001 10:00
To: 'xsl-list@xxxxxxxxxxxxxxxxxxxxxx'
Subject: [xsl] keys and performance



I am using XSLT to convert between two sets of values, using a "table"
defined in XML and a key.
Does the way the table is structured effect performance for large tables? 
For example, is either one of the following two structures better than the
other?
Or is there a better way?

Version 1: used elements will the keys stored as attributes
	<xsl:key name="CountryCodeKey" match="csl:CountryCode/csl:value"
use="@key"/>
	<csl:CountryCode default="Other">
		<csl:value key="IE">Ireland</csl:value>
		<csl:value key="FR">France</csl:value>
		<csl:value key="NL">Netherlands</csl:value>
		<csl:value key="JP">Japan</csl:value>
		<csl:value key="AU">Australia</csl:value>
	</csl:CountryCode >


Version 2: Uses separate elements for the keys and values
	<xsl:key name="CountryCodeKey" match="csl:CountryCode/csl:value"
use="preceding-sibling::cs:key[1]"/>
	<csl:CountryCode>
		<csl:key>IE</csl:key>
		<csl:value>Ireland</csl:value>
		<csl:key>FR</csl:key>
		<csl:value>France</csl:value>
		<csl:key>NL</csl:key>
		<csl:value>Netherlands</csl:value>
		<csl:key>JP</csl:key>
		<csl:value>Japan</csl:value>
		<csl:key>AU</csl:key>
		<csl:value>Australia</csl:value>
	</csl:CountryCode >

Thanks,

James Pasley

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