xsl:if or xsl:applytemplate which one has better memroy usage - xslt

Question

Lets say that I have a input like following.
<country>
<name>countryname</name>
<capital>captialname</capital>
<population>19000</population>
</country>
I'm trnsforming element names to lets say upper code using an xsl. Child elements of country may not occur sometimes. So I can write my transformation as follows.
<xsl:template match="country">
<xsl:element name="COUNTRY">
<xsl:apply-templates select="name" />
<xsl:apply-templates select="capital" />
<xsl:apply-templates select="population" />
</xsl:element>
</xsl:template>
<xsl:template match="name">
<xsl:element name="NAME">
<xsl:value-of select="." />
</xsl:element>
</xsl:template>
<xsl:template match="capital">
<xsl:element name="CAPITAL">
<xsl:value-of select="." />
</xsl:element>
</xsl:template>
<xsl:template match="population">
<xsl:element name="POPULATION">
<xsl:value-of select="." />
</xsl:element>
</xsl:template>
or I can do it as follows.
<xsl:template match="country">
<xsl:element name="COUNTRY">
<xsl:if test="name">
<xsl:element name="NAME">
<xsl:value-of select="." />
</xsl:element>
</xsl:if>
<xsl:if test="capital">
<xsl:element name="CAPITAL">
<xsl:value-of select="." />
</xsl:element>
</xsl:if>
<xsl:if test="population">
<xsl:element name="POPULATION">
<xsl:value-of select="." />
</xsl:element>
</xsl:if>
</xsl:element>
I'm wondering which way it'd use less memory. The actual code I have goes around seven levels deep inside templates. So what I need to know is if I don't use use templates for simple elements will if improve memory usage.

Answer 1

As per my understanding first one is good. Just change:
<xsl:apply-templates select="name" />
<xsl:apply-templates select="capital" />
<xsl:apply-templates select="population" />
To
<xsl:apply-templates/>
only and don't worry about child element if they are not coming sometimes XSLT would take care it.

Answer 2

I think you are approaching from the wrong way. Your current XSLT templates isn't very flexible. You would have contantly amend it for new elements being added.
Instead you should be using the identity transform, and including a template to match any generic element, outut the name as upper case.
Try this XSLT
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="#*|node()[not(self::*)]">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="*">
<xsl:element name="{upper-case(local-name())}">
<xsl:apply-templates select="#*|node()"/>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
Note the the following template matches any element and converts the name to upper case
<xsl:template match="*">
Whereas the other template match will match attributes or any other nodes other than elements, and just copies them as-is
<xsl:template match="#*|node()[not(self::*)]">
Note that this solution would not work if the XML had namespaces defined, but it wouldn't take much tweaking to get it to cope.