It's been a while, so I may be missing something, but do we already have fixed-size lists? If not, I don't see why we'd try to make this fit into a List-shaped problem.
A tuple would be a better fit from that perspective, but as you point out it has the problem of allowing nulls. The key thing about a vector is that unlike lists or tuples you really don't care about individual elements, you care about doing vector and matrix multiplications with the thing as a unit. That's the key reason that it makes more sense to me as a separate type. (Maybe this is making the case for VECTOR FLOAT[N] rather than FLOAT VECTOR[N].) On Wed, Apr 26, 2023 at 4:31 PM Andrés de la Peña <adelap...@apache.org> wrote: > If we are going to use FLOAT[N] as sugar for another CQL data type, maybe > tuples are more convenient than lists. So FLOAT[N] could be equivalent to > TUPLE<FLOAT, FLOAT, ..., FLOAT>. > > Differently to collections, tuples have a fixed size, they are always > frozen and I think they don't support random access. These properties seem > desirable for vectors. > > Tuples however support null values, whereas collections doesn't. I mean, > you can remove elements from a collection, but I think you are never going > to see an explicit null in the collection. Tuples don't allow to remove a > value, but the entire tuple can be written with null values. Like in INSERT > INTO t (key, tuple) VALUES (0, (1, null, 3)). > > On Wed, 26 Apr 2023 at 21:53, Mick Semb Wever <m...@apache.org> wrote: > >> My inclination then would be to say you declare an ARRAY<FLOAT, N> (which >>> is semantic sugar for FROZEN<LIST<FLOAT, N>>). This is very consistent with >>> our existing style. We then simply permit such columns to define ANN >>> indexes. >>> >> >> >> So long as nulls aren't a problem as David questions, an alternative is: >> >> FLOAT[N] as semantic sugar for LIST<FLOAT, N> >> >> And ANN requiring FROZEN<FLOAT[N]> >> >> Maybe taking a poll in a few days will be positive to keep this >> moving forward. >> > -- Jonathan Ellis co-founder, http://www.datastax.com @spyced
