[xquery-talk] MarkLogic using JSONiq for processing JSON ?

daniela florescu dflorescu at me.com
Sat May 9 21:49:48 PDT 2015


Ghislain,

just a simple remark about the hypocrisy and/or naivety and/or lack of technical skills in the design of XQuery 3.1.

You say that , unlike JSONiq, it’s NOT designed as a query language for JSON, and that’s why it fails so short in that respect.

If it is NOT designed as a query language for JSON, why did you bother introducing the notion of the JSON nulll  in XQuery 3.1 at all !?
(I mean, why not the null pointer from Java !??? Or some Scala structures !??)

Pick your choose: 
- either XQuery 3.1 was intended to query JSON, and then it failed, or
- XQuery 3.1 was NOT intended to query JSON, and then it’s damn weird.


Dana




> On May 8, 2015, at 5:46 AM, Ghislain Fourny <g at 28.io> wrote:
> 
> Hi,
> 
> My understanding of the reason why XQuery 3.1 and JSONiq diverge is
> also use-case based. If you are interested in some more background, I
> believe there were two drivers all along:
> 
> 1. Support for NoSQL document store querying.
> 2. Support for map and array structures in memory.
> 
> Both use cases are important, even if their importance varies from
> project to project or from company to company.
> 
> JSONiq was designed 100% for NoSQL document store querying : it is (on
> purpose) optimized for supporting use case 1 and only use case 1.
> 
> XQuery 3.1 also covers use case 2. Supporting both use cases and
> making compromises between the two was not trivial, which is why there
> was a lot of work put into the discussions and the design in the
> working group.
> 
> I share Adam's feeling 100%. Everybody took the time to patiently
> listen to one another, which is one of the aspects of the working
> group I valued the most. I enjoyed each meeting we had and learned a
> lot from the discussions -- paradoxically, I also had the feeling of
> knowing JSONiq better after having them.
> 
> To me, one of the main concrete technical differences (if I correctly
> remember) is that JSONiq manipulates trees/documents (both with XML
> and JSON), so that when you put data into an object, it is copied over
> (even if most of the time the optimizer can spare the actual copying).
> This eliminates many serialization issues when data gets roundtripped
> around. XQuery 3.1 is more data-structure oriented as use case 2
> requires retaining the original identity of map and array values,
> which theoretically allows graphs. This difference is important and
> noticeable when updates and scripting kick in.
> 
> Of course, for each set of use cases, standards and interoperability
> are always desirable, so I can understand Dana's discomfort. I also
> think, though, that it is natural for different languages to emerge if
> the use cases differ and, in the broader context of IT, think that it
> is wise to pragmatically select technologies based on what one wants
> to achieve.
> 
> On the bright side also: the data models behind the languages are
> similar, and both languages can run on the same virtual machine. Zorba
> already supports XQuery 3.0 and JSONiq side by side.
> 
> I hope it makes sense.
> 
> Kind regards,
> Ghislain
> 
> 
> On Fri, May 8, 2015 at 1:21 PM, Adam Retter <adam.retter at googlemail.com> wrote:
>>> No, all the arguments were all technical
>>> 
>>> Getting agreement on all these points was a very lengthy process with much heated argument. Although the decisions made were not always the ones I personally advocated, I think the final language works well.
>> 
>> Absolutely! Whilst I am more of an occasional frequenter and
>> contributor to the XQuery WG, having seen the level of collaborative
>> work and perseverance that that has gone into adding Maps and Arrays
>> to XQuery, I can say that I am impressed.
>> 
>> From my perspective, it was a difficult process, but everyone worked
>> hard together and the technical arguments were always foremost. Whilst
>> working under the constraints of backwards compatibility and creating
>> a cohesive data model and language, I think the result speaks for
>> itself. Certainly many of eXist's users are very happy with the new
>> Maps and Arrays work in XQuery 3.1 and we frequently receive positive
>> feedback on this.
>> 
>> 
>> 
>> --
>> Adam Retter
>> 
>> skype: adam.retter
>> tweet: adamretter
>> http://www.adamretter.org.uk
>> _______________________________________________
>> talk at x-query.com
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> _______________________________________________
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