[xquery-talk] FLOWR vs Xpath axis syntax - Performance
mike at saxonica.com
Wed Aug 1 01:22:17 PDT 2012
On 31/07/2012 17:25, Ihe Onwuka wrote:
> I vaguely remember reading somewhere that a preference for what I
> would call axis notation has performance advantages over the
> equivalent FLOWR code.
> I certainly recall reading that XPath predicates perform better than
> where clauses in FLOWR.
> I would appreciate clarification, confirmation or correction and
> general enllightenment.
As others have said, this is likely to vary between implementations.
I know that some implementations attempt to rewrite FLWOR expressions as
path expressions, while other implementations try to do the opposite.
Presumably in such implementations, if the rewrite succeeds, then it
doesn't matter which way you write the query.
Do some measurements, and share the results with the list, then we can
all be enlightened.
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