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Re: Property Path Profiles

From: Lee Feigenbaum <lee@thefigtrees.net>
Date: Mon, 11 Jan 2010 13:33:11 -0500
Message-ID: <4B4B6EE7.6030301@thefigtrees.net>
To: matthew.perry@oracle.com
CC: W3C SPARQL Working Group <public-rdf-dawg@w3.org>

Matt Perry wrote:
> Hi,
> 
> During the last TC, I mentioned the possibility of a Property Paths 
> profile that identifies a subset of property path queries that can be 
> expressed with SQL. Such a profile would make it easy for triple stores 
> implemented on top of relational databases to identify the set of 
> property path queries that they "natively" support.  The purpose of this 
> email is to start a discussion about the possibility of property path 
> profiles.
> 
> The grammars below show two possible fragments that we have identified. 
> The first grammar is for SQL + CONNECT BY (Oracle) and the second is for 
> PLAIN SQL.
> 
> CONNECT BY:
> 
> ALT  -> URI | URI|ALT
> SEQ  -> URI | URI/SEQ
> Elem -> URI | SEQ   | ALT   | ^URI
> COMP -> URI | Elem* | Elem+ | Elem{n,m} | Elem?
> TOP  -> URI | COMP  | ALT   | SEQ       | ^URI
> 
> PLAIN SQL:
> 
> ALT  -> URI | URI|ALT
> SEQ  -> URI | URI/SEQ
> Elem -> URI | SEQ       | ALT   | ^URI
> COMP -> URI | Elem{n,m} | Elem?
> TOP  -> URI | COMP      | ALT   | SEQ   | ^URI

Are the Plain SQL set simply the set that can be expanded as a (possibly 
complicated) SPARQL 1.0 query string? (This is sort of but not exactly 
what's termed a "simple path" in the current doc.)

Do other DBMSes included equivalent/similar functionality to CONNECT BY? 
I'm hesitant to go down a multi-level conformance path in the first 
place, but I'd be even more hesitant to do so if it were just in the 
context of a single DBMS.

Lee

> 
> Thanks,
> Matt
> 
> 
> 
> 
Received on Monday, 11 January 2010 18:33:48 GMT

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