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The feed of latest orders

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The feed of latest orders

The admin panel's main screen shows twenty fresh orders. To hand back twenty rows, the machine sorts a hundred and fifty thousand. There is no filter here at all — only an order. An index can hand out an order ready-made: it is stored sorted. Make sure no Sort node is left in the plan.

Speed this query up with an index
SELECT * FROM orders ORDER BY created_at LIMIT 20
Solution requirement
Just CREATE/ALTER/DROP — no trailing SELECT needed.

What counts as solved

You may only change the schema: indexes and ANALYZE. The query stays as the task wrote it — no need to send it back.

  • the plan has no Sort
  • the plan has no Seq Scan on orders
  • the query reads at most 12 8 KB pages

Grading runs on a larger dataset than the samples show — the answer has to hold at scale.

PostgreSQLv16
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