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  • 2 + 2 = ?

    As a concise example of the evils of type coercion I came up with the following: INSERT INTO t VALUES ( CAST(2 AS INT), CAST(2 AS INT)); SELECT CASE WHEN x + z = 4 THEN '4' ELSE 'NOT 4' END xPLUSz FROM t; Result: xPLUSz ------ NOT 4 It is left as an exercise for the reader to work out what types x and z ...
    Posted to Data Based (Weblog) by David.Portas on August 26, 2009
  • The Relational Model turns 40

    The Relational Data Model is 40 years old. Edgar Codd first described the idea that databases could be constructed from mathematical relations in an internal IBM Research report in August 1969. The following year his more famous paper on the same topic was published for public consumption. So began a revolution. Data was liberated from its ...
    Posted to Data Based (Weblog) by David.Portas on August 18, 2009
  • Not the model, Bill

    According to InfoWorld, Bill Gates thinks that declarative modelling of business logic has not caught on because of "weak models". This is a surprise. E.F.Codd's earliest papers on the Relational Model described a relational calculus for the purpose of supporting declarative business logic. Even the SQL standards committee added ...
    Posted to Data Based (Weblog) by David.Portas on February 12, 2008
  • Relational database pioneer doesn't quite say technology is obsolete!

    According to Computerworld, Mike Stonebraker says "RDBMSes, are 'long in the tooth' and 'should be considered legacy technology'". Knowing Stonebraker's work and reputation that seemed like some pretty startling information! It was less of a surprise to find that Computerworld hadn't quite got it right ...
    Posted to Data Based (Weblog) by David.Portas on September 16, 2007
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