Mailing-List: contact users-help@cocoon.apache.org; run by ezmlm
Precedence: bulk
Reply-To: users@cocoon.apache.org
Received-SPF: neutral (hermes.apache.org: local policy)
Message-ID: <419DCD65.9090004@upaya.co.uk>
Date: Fri, 19 Nov 2004 10:39:33 +0000
From: Upayavira <uv@upaya.co.uk>
User-Agent: Mozilla Thunderbird 0.7 (Windows/20040616)
MIME-Version: 1.0
To: users@cocoon.apache.org
Subject: Re: Large XML transformations in Cocoon.
References: <s19dbf6c.022@cs-emo.csir.co.za>
In-Reply-To: <s19dbf6c.022@cs-emo.csir.co.za>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit

Derek Hohls wrote:

>OK, I'll bite here, as my curiosity is aroused (and, lets face it,
>as XML gets wider use, its likely that file sizes will get larger)
>
>You say "XSLT isn't that appropriate for that sort of thing";
>I thought XSLT was *the* preferred way for processing XML?!
>  
>
Because XSLT can, in various circumstances, build in memory versions of 
our XML. If your XML is large, you will consume a lot of memory, which 
could break things. STX (which I have never used), is intended to be a 
streaming process, which means that you don't hold any of your XML in 
memory, and you can thus stream as much XML as your recipient can handle.

>Second; what are the advantages/disadvantagesof STX  icw XSLT?
>  
>
Advantage of STX? It is streamed. Disadvantage of STX? It is streamed. 
As I say, I've never used it, but I suspect there are some things that 
require 'knowledge' of different parts of the XML structure that could 
be difficult to implement in STX. But then, I might be wrong.

Regards, Upayavira

>>>>uv@upaya.co.uk 2004/11/19 09:09:18 AM >>>
>>>>        
>>>>
>Tom Bloomfield wrote:
>
>  
>
>>I'm planning to do xml -> text transformations (for tab-delimited 
>>output) and xml -> FOP on large XML datasets.  The XML I will  be 
>>processing will be 10-12 MB in size, and will grow from there. Based
>>    
>>
>
>  
>
>>on planning, the XSL will contain around 50 node traversals and will
>>    
>>
>
>  
>
>>iterate over my XML dataset around 46,000 times.  Previous to this,
>>    
>>
>my 
>  
>
>>Cocoon transformations haven't been nearly this big.
>>
>>The amount of JVM memory I have to deal with is limited (<256M). 
>>    
>>
>This 
>  
>
>>transformation will need to run in real-time.
>>Does anyone have experience dealing with large datasets like this?
>>    
>>
>
>That sounds like quite a challenge. XSLT isn't that appropriate for
>that 
>sort of thing. Firstly, in XSLT, avoid arbitrary wanders around your
>XML 
>tree - stay as close to the context node as you can.
>
>Alternatively, look at STX (there is an STX block). See if you can 
>manage your transformations with that. This is "streaming" 
>transformations for XML, i.e. it is designed for streaming, and thus 
>should be able to handle large datasets.
>
>Regards, Upayavira
>
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: users-unsubscribe@cocoon.apache.org 
>For additional commands, e-mail: users-help@cocoon.apache.org 
>
>
>  
>


---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@cocoon.apache.org
For additional commands, e-mail: users-help@cocoon.apache.org