Welcome to EMC Consulting Blogs

August 2009 - Posts

• 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 Read More... Posted 26 August 2009 21:02 by David.Portas | 3 Comments Filed under: SQL, Data

• 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 Read More... Posted 18 August 2009 22:55 by David.Portas | 3 Comments Filed under: Cloud, SQL, Data