[seek-dev] implement XQuery in EcoGrid and SRB

[Dave Vieglais]

Hi Bing,

Your argument and examples below assume that all data sources 
contributing to the ecogrid shall conform to a common schema, which 
seems overly restrictive even though it does make building XQuery 
statements a bit easier since you are then working with a single schema.

I'm not sure that this is the intent of the ecogrid implementation, but 
please correct me if I'm mistaken.

regards,
   Dave V.


Bing Zhu wrote:
> Peter and Jing,
> 
> The whole EcoGrid data stored in metacat, SRB, (others), can be viewed as a
> virtual XML document (or a DOM object). This DOM object has at least two
> sub-nodes,
> metacat and srb.
> 
> Since SRB is organized in collection and sub-collection hierarchical
> architecture, each collection is a subnode in the XML tree under
> (/EcogGrid)/srb. (Actually
> we can define a XML schema for our EcoGrid data. ). Thus we can implement
> XQueries in
> our EcoGrid to act as a common query engine across different systems
> (metacat, SRB, etc.)
> 
> I compiled some examples of XQueries to search documents in SRB.
> 
> (1)	Search all design documents stored in SRB collection,
> /home/bzhu.sdsc/designDocs,
>       which were created before Sept 23, 2002.
> 
>             for $e in document(“EcoGrid.xml”)/srb/home/bzhu.sdsc/designDocs
>             where $e/@objtype = “file” and $e/@time lt date(“09-23-2002”)
>             return <datasrc>SRB</datasrc><dataname>$e/@name</dataname>
> 
> (2)	find all datasets stored in SRB which  have titles containing “protein”
> and
>       are owned by Professor John whose user name is john.
> 
>             for $e document(“EcoGrid.xml”)/srb/home//
>             where $e/@objtype = “file” and
>                   contains($e/@name like, “protein”) and
>                   contains($e/@owner, “john”)
>             return <datasrc>SRB</datasrc><dataname>$e/@name</dataname>
> 
> 
> Jing, Would you provide some examples (or info) regarding searching in
> metacat?
> 
> And We also can start with designing a XML schema for whole EcoGrid data
> model
> based on following (roughly).
> 
> EcoGrid
>      Metacat
>           …
>      SRB
>         collection (attribute: objtype, time, owner, …)
>              dataset (attribute: objtype, time, owner, size, container,
> resource, …)
>                   user-defined metadata
>      other data source
> 
> 
> Cheers,
> Bing
> 
> =====================================================
> Bing Zhu
> San Diego Supercomputer Center
> bzhu at sdsc.edu
> (858)534-8373
> =====================================================
> 
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