Is the XML Output stage *really* this slow?

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chulett
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Is the XML Output stage *really* this slow?

Post by chulett »

Just spent the last three (long) days taking my first foray into the Wonderful World of DataStage and XML. :shock:

Working from an Ascential 'Best Practices' guide we built all of the optional pieces as XML 'chunks' written to hashed files via the XML Output stage. Building all of the chunks was not a big deal, once we got the technique down and running them didn't take an inordinate amount of time. About half a million source rows from Oracle up into about a dozen hashed files in 15 minutes or so. Fine so far.

Last merger job is very simple - stream in staged Oracle keys, hit all the hashed files for the appropriate chunks per row in lookups from one transformer and then shove them through the XML Output stage one last time, this time as a complete document written to disk. This is the part that is mind-numbingly slow... I left it running at a whopping 5 rows per second. Granted, these are wide XML rows, but still. Jeez.

I know this is kind of nebulous, but any general tidbits people here have for dealing with these XML stages, tricks to speed the puppies up? :cry:
-craig

"You can never have too many knives" -- Logan Nine Fingers
vmcburney
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Post by vmcburney »

Could you run a version writing to a sequential file (don't worry about XML tags) and post the comparison figures. Would be interesting to know what hte overhead of the XML Output is over a standard sequential file write. Probably fixed width sequential is the closest match to XML output.
chulett
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Post by chulett »

Definitely on the plate for sometime today, assuming it finishes. At this point I have no idea where the overhead is here - in the actual writing of the XML or the looking upping of the big chunks. Or both. :?
-craig

"You can never have too many knives" -- Logan Nine Fingers
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