A tree encodes a mandatory path or navigation to get to some piece of data. But not every piece of knowledge has a "true" path.
Whereas a relation ("table" in its crude form) can be queried and projected into many forms (including as a tree) but with multiple paths to the same data and ensure future uses are not trapped in a mandatory hierarchy. This was Codd's entire discovery and it still holds 50 years later.
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A tree encodes a mandatory path or navigation to get to some piece of data. But not every piece of knowledge has a "true" path.
Whereas a relation ("table" in its crude form) can be queried and projected into many forms (including as a tree) but with multiple paths to the same data and ensure future uses are not trapped in a mandatory hierarchy. This was Codd's entire discovery and it still holds 50 years later.