Status: IN
Hash index storage is fundamentally memory-bound: every key must reside in RAM for the single-seek O(1) read path, making dataset size directly constrained by available memory with no spill-to-disk fallback.
The O(1) read guarantee is inseparable from the all-keys-in-memory constraint — one cannot exist without the other
Depends on (SL): hash-index-all-keys-in-memory, hash-index-keys-must-fit-in-ram, hash-index-read-is-single-seek