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GeneralRe: Microsoft Visual Studio 2013 review Pin
Kornfeld Eliyahu Peter12-Nov-13 19:34
professionalKornfeld Eliyahu Peter12-Nov-13 19:34 
GeneralRe: Microsoft Visual Studio 2013 review Pin
Marco Bertschi12-Nov-13 22:01
protectorMarco Bertschi12-Nov-13 22:01 
NewsWhat happened to the buzz around NoSQL? Pin
Kent Sharkey12-Nov-13 10:46
staffKent Sharkey12-Nov-13 10:46 
GeneralRe: What happened to the buzz around NoSQL? Pin
Marc Clifton12-Nov-13 14:05
mvaMarc Clifton12-Nov-13 14:05 
GeneralRe: What happened to the buzz around NoSQL? Pin
Kent Sharkey12-Nov-13 14:25
staffKent Sharkey12-Nov-13 14:25 
GeneralRe: What happened to the buzz around NoSQL? Pin
Rob Grainger14-Nov-13 1:46
Rob Grainger14-Nov-13 1:46 
GeneralRe: What happened to the buzz around NoSQL? Pin
Marc Clifton14-Nov-13 1:55
mvaMarc Clifton14-Nov-13 1:55 
GeneralRe: What happened to the buzz around NoSQL? Pin
Rob Grainger14-Nov-13 12:02
Rob Grainger14-Nov-13 12:02 
"Isn't that something that a unique constraint could handle?"

That's certainly true, but in the Relational Model, duplicate rows are expressly forbidden - even in queries. Row IDs are really a workaround, rather than a solution to the issue, and also violate the constraint that their should be no ordering in base relations (tables).

This hit me this week at work, where a (pre-existing) query was actually returning two rows rather than one and effectively selecting which one actually gets returned by some logic I was unaware of. This was then updated in code, leading directly to data inconsistencies. Had the original developer used UNIQUE, the result would not have been updateable and the problem could not occur.

Another key feature of domains is also worth considering. Each PK in the database is a unique domain. Joins can only be performed based on data from a common domain - this is (rightly) much more restrictive than the joins as implemented in mainstream DBMS. Again, I have seen this error occur in practice (although only once) with disastrous consequences.

Further, in V2 of the Relation Model (which has more rules and features), PK domains are database-wide: multiple tables may draw PK values from the same domain - but each PK value is still a unique identifier, that may be a PK value in more than one table. This feature could really help with object-relational mapping, so a table representing a subclass can share a PK with the table representing the base class without the need for special work to maintain consistency between the two. (It brings many other benefits too).
"If you don't fail at least 90 percent of the time, you're not aiming high enough."
Alan Kay.

GeneralRe: What happened to the buzz around NoSQL? Pin
Marc Clifton17-Nov-13 10:52
mvaMarc Clifton17-Nov-13 10:52 
NewsWhat makes Java developers more productive? Pin
Kent Sharkey12-Nov-13 10:36
staffKent Sharkey12-Nov-13 10:36 
GeneralRe: What makes Java developers more productive? Pin
Marc Clifton12-Nov-13 13:59
mvaMarc Clifton12-Nov-13 13:59 
GeneralRe: What makes Java developers more productive? Pin
Nagy Vilmos12-Nov-13 22:12
professionalNagy Vilmos12-Nov-13 22:12 
GeneralRe: What makes Java developers more productive? Pin
Marc Clifton19-Nov-13 13:46
mvaMarc Clifton19-Nov-13 13:46 
GeneralRe: What makes Java developers more productive? Pin
Kornfeld Eliyahu Peter12-Nov-13 19:38
professionalKornfeld Eliyahu Peter12-Nov-13 19:38 
GeneralRe: What makes Java developers more productive? Pin
Rob Grainger14-Nov-13 2:14
Rob Grainger14-Nov-13 2:14 
News2013 developer salary survey Pin
Kent Sharkey12-Nov-13 8:06
staffKent Sharkey12-Nov-13 8:06 
GeneralRe: 2013 developer salary survey Pin
DaveAuld12-Nov-13 8:35
professionalDaveAuld12-Nov-13 8:35 
GeneralRe: 2013 developer salary survey Pin
NormDroid12-Nov-13 8:45
professionalNormDroid12-Nov-13 8:45 
GeneralRe: 2013 developer salary survey Pin
DaveAuld12-Nov-13 10:02
professionalDaveAuld12-Nov-13 10:02 
GeneralRe: 2013 developer salary survey Pin
thatraja12-Nov-13 19:45
professionalthatraja12-Nov-13 19:45 
AnswerRe: 2013 developer salary survey Pin
Eddy Vluggen12-Nov-13 9:14
professionalEddy Vluggen12-Nov-13 9:14 
GeneralRe: 2013 developer salary survey Pin
Zombie Code Monkey12-Nov-13 18:11
Zombie Code Monkey12-Nov-13 18:11 
GeneralRe: 2013 developer salary survey Pin
Kornfeld Eliyahu Peter12-Nov-13 19:43
professionalKornfeld Eliyahu Peter12-Nov-13 19:43 
GeneralRe: 2013 developer salary survey Pin
Dan Neely13-Nov-13 2:35
Dan Neely13-Nov-13 2:35 
NewsMicrosoft axes its controversial employee-ranking system Pin
Kent Sharkey12-Nov-13 7:46
staffKent Sharkey12-Nov-13 7:46 

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