I'm not sure why you think integrity constraints are purely logical. Primary keys are physical constraints. They enforce that the primary key remains unique. Here's an example of SQL that creates a physical foreign key constraint.
ALTER TABLE FactInventoryCollections
FOREIGN KEY (ClientPK)
Physical constraints allow the database engine to return an error if an operation attempts to insert a row that violates any defined constraints. --LinkedIn.com
2. To Laugh or Cry?
3. Online Debunkings
- Comments: Atomicity and its reinterpretation
- Comments: Corporate Data Model re-defined as Enterprise Data Model (EDM)
4. Interesting Elsewhere
David McGoveran has been working on a book tentatively titled LOGIC FOR SERIOUS DATABASE FOLKS intended to set some matters straight regarding the formal, set-theoretic and logic foundations of the RDM which have been misinterpreted. While he is not ready to publish yet, I asked and he agreed to post at his site a draft of a chapter on view updating which I consider a must read (together with the Introduction), particularly since it exposes the thinking behind the Principle of Orthogonal Design rejected by Date and Darwen.
5. New Links
Added the following to the LINKS page:
6. And now for something completely different
Demis Hassabis, Founder of DeepMind Technologies and Artificial-Intelligence Wunderkind at Google, Wants Machines to Think Like Us | MIT Technology Review Demis Hassabis, Founder of DeepMind Technologies and ... The man behind a startup acquired by Google for $628 million plans to build a revolutionary new artificial intelligence ... At Harrah’s Casino on the shores of Lake Tahoe, DeepMind researchers showed off software that had learned to play classic Atari games including Space Invaders and Pong better than any human.Can't get deeper than this!
- Susan Rice tells AIPAC zero enrichment deal with Iran 'simply unattainable'
- In lieu of nuclear deal, US and Iran likely to extend talks
- Obama tells Iran to grasp 'historic' chance
- Khamenei calls 'Death to America' as Kerry hails progress on nuke deal
- Iran’s leader calls Obama a liar
The oldest hatred
- Obama continues to blast Netanyahu, reassesses options
- US Preparing for a Post-Israel Middle East
- Obama PM's anti-Arab remarks risk eroding Israeli democracy
- Israel Beware of Obama
- For Obama, Bibi’s words matter while Iran’s don’t
- Kerry concedes that US must talk to Assad
Middle East Reality Check
- ‘Urgent need’ for unified Arab force to counter radicals
- War on ISIS is “going fine” but hindered by Iraqi divisions
- Iraqi Sunnis accuse Shi'ite paramilitaries of burning homes
- Unified Arab force A triple oxymoron
This week's video
This week's book
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