A retrieval data structure implements a mapping from a set $S$ of $n$ keys to range $R=\{0,1\}^r$, e.g.
given by a list of key-value pairs $(x,v)\in S\times R$, but an element outside $S$ may be mapped to any value.
Asymptotically, minimal perfect hashing allows to build such a data structure that needs 
$n\log_2 e + nr+ o(n)$ bits of memory and has constant evaluation time.
Recently, data structures based on other approaches have been proposed that have linear construction time,
constant evaluation time and space consumption $O(nr)$ bits or even $(1+\eps)nr$ bits for arbitrary $\eps>0$.
This paper explores the practicability of one such theoretically very good proposal,
bridging a gap between theory and real data structures.