On 1/20/13 10:22 AM, John F Sowa wrote:
> Peter P. Chen published his paper on the E-R model in 1976. The basic
> notation is based on Bachman diagrams from the 1960s. The information
> expressed in E-R diagrams includes type constraints and cardinality
> constraints that are just as important for formal mathematics as
> they are for practical DBs of any kind. (01)
Yes, I am not disagreeing with that [1]. SQL-3 adds references as data
types for RDBMS table definition, this is something that Stonebraker and
his team demonstrated via Illustra [2][3] during the Object-Relational
era. The issue is that via SQL you need to be able to be able to perform
the following tasks: (02)
1. Use DDL to add fields/columns/attributes of type reference
2. Use a de-reference function to dereference the tuples scoped to a
reference. (03)
The problem with this approach are as follows: (04)
1. The references are DBMS specific
2. The function signatures vary per DBMS. (05)
Here's how a Web of Linked Data dimension addresses the problems above
via the RDF data model and SPARQL query language: (06)
1. De-referencable URIs (hyperlinks) are the reference mechanism
2. References resolve to description graphs
3. Description graphs are based on the entity relationship model
enhanced with URIs and explicit machine readable entity relationship
semantics -- what the RDF model is about albeit not so obvious from its
promotional literature
4. SPARQL query language that leverages the above -- key thing being
that the queries don't require a de-reference function with varied
signatures per system . (07)
As a result of the above, Facebook is a data space on the Web just like
Oracle is a data space on a local enterprise network. You can query
Facebook data using SPARQL just as you could using their own native
SQL-Like query language, but with much more power since the URI
references enable construction and access to data beyond Facebook e.g.,
to Google+, Twitter, LinkedIn etc.. (08)
>
> KI
>> >Ask the folks behind that [IBM Watson] project and they will tell you
>> >how much the LOD cloud contributed to Watson's smarts.
> Yes, indeed. They gather up all that data from everywhere, and they
> store it and process it in -- guess what? -- DB2. A relational DBMS! (09)
A DB2 relational dbms that in version 10 is enhanced with RDF data model
storage and SPARQL query language support :-) (010)
>
> John (011)
Links: (012)
1. http://ontolog.cim3.net/forum/ontolog-forum/2012-11/msg00060.html .
2. http://dl.acm.org/citation.cfm?id=546685 .
3.
http://books.google.com/books/about/Object_relational_DBMSs.html?id=QMpQAAAAMAAJ (013)
.
4. http://www.snee.com/bobdc.blog/2012/08/ibms-db2-as-a-triplestore.html . (014)
-- (015)
Regards, (016)
Kingsley Idehen
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca handle: @kidehen
Google+ Profile: https://plus.google.com/112399767740508618350/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen (017)
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