SQL is not relational algebra but rather an attempt to bridge a relational algebra/programming gap. The null issue arises in SQL due to it being used in a relational algebra context in one case and a software development context in another. The point though is that these are treated as equivalents because of an open world assumption.
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SQL is not relational algebra but rather an attempt to bridge a relational algebra/programming gap. The null issue arises in SQL due to it being used in a relational algebra context in one case and a software development context in another. The point though is that these are treated as equivalents because of an open world assumption.