[xsl] Lookup tables

[Kamal Bhatt <kbhatt@xxxxxxxxx>]

Hi
My company is designing XML specifically for XSLT processing. A question 
that has come up is the use of lookup tables. We have a lot of repeated 
data, and our system  architect would like that data put in a "lookup 
table" at the top of the XML. By lookup table I mean XML with some key 
that can be identified. The only way I can think of processing this XML 
in XSLT 1.0 (without a lot of '..') is to use something like

ancestor::node()//LookUp/Parameter[@key = 'key_to_lookup'].

First question, is there another way of doing this, secondly, in XSLT 
parsers, particular those that use SAX, is there a major performance hit 
in using this method over having the data repeated.

Personally, I would prefer avoiding ancestor::node() and I would 
definitely like to avoid //.

Cheers.

--
Kamal Bhatt