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> Joins are not even a thing in graph databases; being able to directly query across edges obviates the entire concept. Joins are the central thing in graph da
by jandrewrogers 5y ago
> Joins are not even a thing in graph databases; being able to directly query across edges obviates the entire concept.
Joins are the central thing in graph databases, even if you don't think of it in those terms or materialize some of the join operations. Being able to directly query across edges is a logical operation, it doesn't imply the underlying implementation. While the simple "node/edge" model in memory seems easy, it also has pathologically poor locality so most graph databases use less direct representations (traversed with join operations under the hood) with much higher average performance.
- eurasiantiger 5y agoYou could make the same argument for any columnar store. Getting fields from one is fast, though, independent of the table they belong to. Joining together row-based tables has more moving parts and much more runtime cost.