On 4/4/22 09:21, J. Roeleveld wrote:
This was actually the case, I forgot there is 1 NULL-value in that list.
Personally, I think NULL should be treated as a seperate value and not lead to
strange behaviour.
NULL is strange. Relational databases use ternary, not binary logic. In the woke vernacular, one could say that Postgres is non-binary. NULL literally means "no value". It is a part of the standard, so we have to deal with it, Codd help us. However, based on my lifelong experience with Oracle, NULL values are bad and are best avoided. Postgres is more forgiving than Oracle because in Postgres, the condition "is not null" can be resolved by index. In Oracle, it can not.
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Mladen Gogala
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