Polynomially small redundancy for small-value augmented retrieval
Determine whether augmented retrieval with value domain size V = n^{o(1)} (including the case where V is a power of two) admits constant-time queries with polynomially small redundancy n^{1−Ω(1)}.
References
Whether or not one can achieve polynomially small redundancy $n{1 - \Omega(1)}$ for $V = n{o(1)}$ (even assuming, for example, that $V$ is a power of two) appears to remain as an open question, and appears to be a problem that will require significant additional algorithmic ideas to solve.
— Static Retrieval Revisited: To Optimality and Beyond
(2510.18237 - Hu et al., 21 Oct 2025) in Section 6 (Open Problems)