C# XSLT Transforming Large XML Files Quickly

Question

I\'m transforming a > 2GB file with a lookup template in the XSLT. I would like this to run faster but can\'t find any low hanging fruit to improve performance. Any help would b

Answer 1

As an alternative, you might want to look into solving the task with XSLT 3 and its streaming feature (https://www.w3.org/TR/xslt-30/#streaming-concepts) as there you could process the huge input file in a forwards only but declarative way where you only in the template for the attribute element you need to ensure you work with a intentionally created full copy of that element to allow XPath navigation to the child elements. Additionally I think it makese sense to read in the lookup document only once and do the translate calls to create the proper element names only once. So the following is a streaming XSLT 3 solution runnable with Saxon 9.8 EE which transforms the lookup document into an XPath 3.1 map (https://www.w3.org/TR/xpath-31/#id-maps) and otherwise uses a streamable mode to process the large, main input:

    
    
        
            
                text12
                ID
                Varchar2
                30
            
            
                text34
                Last Name
                Varchar2
                30
            
            
                date866
                DOB
                Date
                
            
              
    

    

    

    

    
        
        
            
        
    

Online sample (there running with Saxon 9.8 HE which ignores the streaming and does normal XSLT processing) is at https://xsltfiddle.liberty-development.net/bFDb2Ct/1.

To run streaming XSLT 3 with Saxon 9.8 and C# you use http://saxonica.com/html/documentation/dotnetdoc/Saxon/Api/Xslt30Transformer.html and set up ApplyTemplates on an input Stream with your huge input XML (http://saxonica.com/html/documentation/dotnetdoc/Saxon/Api/Xslt30Transformer.html#ApplyTemplates(System.IO.Stream,Saxon.Api.XmlDestination)).