Hi Yuya, Makes sense — paying 10-20% on inserts for a sketch many queries never touch is a bad trade.
With two NDV types in the spec, what should a reader do when a table has both? Theta and HLL can't be unioned, so a table with older theta blobs and newer HLL ones can't produce one table-level NDV without recomputing. Does a table stick to one family, do readers prefer one, or do mixed tables lose mergeability until a rewrite? Also: should the blob metadata record lgK next to ndv? Otherwise a reader merging across files can't reason about the accuracy of the result. Raghav On Wed, Oct 21, 2026 at 2:40 AM Denys Kuzmenko <[email protected]> wrote: > +1 > -- Thanks Raghav
