LEADER 00000cgm a22004337a 4500 
003    OCoLC 
005    20240129213017.0 
006    m     o  c         
007    cr cn||||||||| 
007    vz czazuu 
008    190704s2014    xx ---            vleng d 
019    1232112337|a1305882605 
024 8  9781491908860 
029 1  AU@|b000067117979 
035    (OCoLC)1107410157|z(OCoLC)1232112337|z(OCoLC)1305882605 
040    OTZ|beng|cOTZ|dOCLCQ|dNZCPL|dOCLCF|dOCLCO|dOCLCQ 
049    INap 
099    Streaming Video O’Reilly for Public Libraries 
100 1  Date, C. J.,|eauthor. 
245 14 The Closed World Assumption|h[O'Reilly electronic 
       resource] /|cDate, C.J.|h[O'Reilly electronic resource] 
250    1st edition. 
264  1 |bO'Reilly Media, Inc.,|c2014. 
300    1 online resource (1 video file, approximately 1 hr., 35 
       min.) 
336    two-dimensional moving image|btdi|2rdacontent 
337    computer|bc|2rdamedia 
338    online resource|bcr|2rdacarrier 
347    video file 
365    |b79.99 
520    The Closed World Assumption (CWA) is an extremely 
       important concept in the database world, despite the fact 
       that it isn't usually spelled out explicitly. Basically 
       what it says is this: Everything stated by the database, 
       either explicitly or implicitly, is true; everything else 
       is false. This presentation explains the CWA in detail and
       shows why it's preferred over its rival, The Open World 
       Assumption (OWA). In particular, it examines the claims, 
       sometimes heard, to the effect that the database community
       operates under the CWA while the semantic web community 
       operates under the OWA. It also explains how "missing 
       information" can be handled without any need for nulls or 
       three-valued logic. The presentation is divided into four 
       modules. Module I lays some important groundwork, 
       discussing predicates and constraints in particular and 
       stressing the importance of database consistency. Module 
       II considers consistency in more detail and then discusses
       a simple example in depth, building to the conclusion that
       the OWA and the relational model are fundamentally and 
       irrevocably at odds with each other (which is why in 
       practice we always adopt the CWA). Module III then goes 
       into more depth on predicates and shows how to get "don't 
       know" answers out of the database (when appropriate) 
       without any need for nulls or three-valued logic (3VL). 
       Finally, Module IV shows how the CWA can even be used in 
       connection with predicates involving negation or 
       conjunction 
533    Electronic reproduction.|bBoston, MA :|cSafari,|nAvailable
       via World Wide Web. 
538    Mode of access: World Wide Web. 
542    |fCopyright © O'Reilly Media, Inc. 
550    Made available through: Safari, an O'Reilly Media Company.
588 0  Online resource; Title from title screen (viewed August 25,
       2014). 
590    O'Reilly|bO'Reilly Online Learning: Academic/Public 
       Library Edition 
710 2  Safari, an O'Reilly Media Company. 
856 40 |uhttps://ezproxy.naperville-lib.org/login?url=https://
       learning.oreilly.com/videos/~/9781491908860/?ar|zAvailable
       for O'Reilly for Public Libraries 
936    BATCHLOAD 
994    92|bJFN