Subject: Re: [xsl] use-when attribute? From: Geert Josten <Geert.Josten@xxxxxxxxxxx> Date: Sun, 19 Dec 2004 22:45:47 +0100 |
Saxon builds the index for each key when that key is first used against a particular document. In general, you don't know which keys will be used for which document, and there's no point building an index for a key that won't be used.
In any case, scanning the nodes is not expensive compared with evaluating the pattern and the use expression, so it doesn't much matter whether it's done in one scan or several. It's not like a database, where disc accesses are expensive and need to me minimised.
Also, forming the union of three node-sets isn't necessarily expensive in a pipelined implementation, especially if the path expressions that produce the three node-sets automatically deliver results in sorted order. (This is another reason for avoiding // - an expression of the form //a/b may need to be sorted, whereas /*/a/b doesn't).
<test> <data> <a>AAAAAAAAA...</a> <b>BBBBBBBBB...</b> <c>CCCCCCCCC...</c> </data> .. (repeated until size was 10Mb) .. </test>
Cheers, Geert
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
RE: [xsl] use-when attribute?, Michael Kay | Thread | RE: [xsl] use-when attribute?, Michael Kay |
Re: [xsl] multiple output targets (, Bruce D'Arcus | Date | RE: [xsl] use-when attribute?, Michael Kay |
Month |