| What was near here, around then? | A range on x, a range on y, a range on z and a range on t: four conditions, a composite index that favours one of them, and a scan over the rest. Fine at thousands of rows, slow at millions, and the planner's choice changes with the data. | Place and time are one address, not four columns. A box in space and a window in time is one lookup, and it stays one lookup at millions of rows. Near in the world is near in the memory. |
| Where was it, before that? | Two queries, or a window function, and you hand-roll the phrasing. | Every object has a history, so “last seen, and before that” is one question, and the answer comes phrased for speech. |
| What changed? | A self-join of the table against itself across two time windows, per label, per room. It works, and it is the query nobody wants to maintain. | “What changed?” is built in: what is new, what moved and how far, what has not been seen, per room, over any window. |
| Is this new? | Not a query. You would need a similarity search over embeddings and a threshold you tune by hand. | The memory knows what it expects to see and scores how surprising a sighting is, so “this is new” and “have I seen this before” are answers, not thresholds you tune. |
| What does the memory look like after a year? | A table that only grows, or a cron job that deletes. Both lose the past. | It ages like memory: recent moments stay sharp, old ones become summaries, storage stays bounded, and last year is still answerable. |
| Ten devices, one memory, patchy networks | Replication, conflict handling and caches, all yours to build. | Many devices write into one memory. A device that was offline catches up with exactly what it missed, and nothing is written twice. |
| Different scales | A room and a city need different indexes and different units. | One address space from a shelf to a warehouse: the memory sharpens where the data is dense, with no second schema for the city. |