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fanout

Calculations run on this device. Scenario values are not sent anywhere — the engine is fully local.

system design calculator · free

Postgres EXPLAIN Lens

Feed cardinality through planner-ish cost math and predict the plan.

Seq scan or index — what does the planner see?

Engine 1.0.0 · calculation
110000000
B
82048
1
1
Planner pick
Index Scan
Seq cost (toy)
1000.0
Index cost (toy)
43.2
Bytes touched
12.00 MB

Selective path favors the index.

rows 100000, index=yes

Method

  • Deterministic local model of the mechanism — knobs recompute outputs instantly with no network.
  • Numbers are teaching approximations, not production capacity guarantees.

Sources

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