[Shelnutt2]

I agree that many use cases of sparse data, uniqueness of the dimensions can't be guaranteed or you might not want to enforce the uniqueness. With the recent TileDB 2.0 release we introduced support for duplicates in sparse arrays which adds the support for multi-sets[1].

[1] https://github.com/TileDB-Inc/TileDB/pull/1504

[jakebol]

Just to note that language "duplicates in sparse arrays" doesn't make sense, if you allow for duplicates it is no longer an array by definition.

[DaiPlusPlus]

Arrays (vectors) can have duplicates - don’t you mean a set?

[evanpw]

I think the duplicates are in the coordinate dimension, like x[1] having more than one value, rather than x[1] and x[2] have the same value.