I know well. I have read most CCDB posts and architecture documentation. Pretty good job. There are several ways to map a row to K-V stores, and different data

I know well. I have read most CCDB posts and architecture documentation. Pretty good job. There are several ways to map a row to K-V stores, and different databases have chosen different approaches, I'm not referring specifically to CCDB's. Whether you do [idA: [valA, valB, valC]] or [id/colA: valA, id/colB: valB, id/colC: valC], what I say is that I believe it is less efficient than [idA, valA, valB, valC], which actually also supports more clearly the case of compound keys (aka [idA, idB, idC, valA, ....]). Both are the ways Postgres stores rows.