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Responses are trees. The store is a graph.

When a response arrives, Relay walks it and writes every object with an id into a flat map of records keyed by that id. Nested objects become references. This is the live store of this tab, drawn directly from environment.getStore().getSource().
Fetching with Relay…
  • why it mattersOne record per entity means one source of truth. Rename a user and every post, comment and avatar that references them is correct, with no manual cache syncing.
  • why it mattersQueries with different shapes share records. The second query adds fields to an existing User rather than creating a stale copy.
  • why it mattersConnections are records too (toggle them on). That's how Relay can append a page of edges or insert a new comment without refetching the list.