indexing

You try to query historical state via RPC calls. You can't cheaply read past state. ethcall reads current state. Reading state at a historical block requires an archive node (expensive, slow). For historical data, you need an indexer.

You loop through blocks looking for events. Scanning millions of blocks with ethgetLogs is O(n) — it will timeout, get rate-limited, or cost a fortune in RPC credits. Use an indexer that has already processed every block.

You store query results onchain. Leaderboards, activity feeds, analytics — these belong offchain. Compute offchain, index events offchain. If you need an onchain commitment, store a hash.

如何讀取和查詢鏈上資料——事件、圖表、索引模式。為什麼不能只循環塊，以及用什麼來代替。 來源：austintgriffith/ethskills。