The waste of abseil's b-tree, for example, is small per value: https://abseil.io/about/design/btree https://abseil.io/about/design/btree The efficiency compare

The waste of abseil's b-tree, for example, is small per value: https://abseil.io/about/design/btree https://abseil.io/about/design/btree The efficiency compared to hash tables very much does carry over to the small b-trees used for in-memory data.