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20011220 draft: indexing support?

From: Tim Bray <twbray@antarcti.ca>
Date: Fri, 8 Feb 2002 18:22:19 -0500 (EST)
Message-ID: <3C645D91.5010909@antarcti.ca>
To: www-xml-query-comments@w3.org
A quick scan through some of the stuff in the Functions and
Operators draft suggests that there's an issue with indexing.
I apologize if there is already a policy in place on this that
I should have read, but: should XQuery worry about the ease
or general possibility of indexing support such that queries
in principle can be resolved in a time that is less than
linear in the size of the dataset?

An example of this is for example is "ends-with" - I was
actually looking at this in one of the use-cases and wondering
how on earth I would actually implement this in a real-world
system; a substantial proportion of content indexing systems
just don't do (and can't be made to do) suffix matching.

More generally, the difficulty of indexing support for
the things that show up in functions & operators is all
over the map.  Maybe conformance levels help here?  I.e.
is there a relatively small subset that can generally
be expected to allow efficient indexing and thus
sublinear performance?

Cheers, Tim Bray
Received on Monday, 11 February 2002 12:39:36 UTC

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