NoSQL

Retain the threshold after narrowing by site

BOTIE

Build and unwrap the selected site bucket. Inspect its whole candidate list before filtering temperature.
Ready to test
0 passed · 0 failed · 1 not run

An empty floor. Start with the information your machine needs.

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Use a copy of the example to try your own data. Keep the problem's assumptions in mind, and predict the effect of a change before checking the output. You can also add another branch to compare two ways of doing the calculation.

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Context for this challenge

Build and unwrap the selected site bucket. Inspect its whole candidate list before filtering temperature.

The register has readings from several sites.

Inspect the component calculation
Use a lookup or its fallback(
  Lookup result: Look up one exact key(
    Keyed records: Collect records under a key(
      Records: Current reading documents
      Field path: site
    )
    Exact key: Requested site
  )
  Value for a missing key: No candidates
)
Examples and results
Current reading documents
[
  {
    "asset_id": "P1",
    "site": "north",
    "temperature": 85
  },
  {
    "asset_id": "P2",
    "site": "south",
    "temperature": 99
  }
]
Requested site
north
No candidates
[]
Required result
[
  {
    "asset_id": "P1",
    "site": "north",
    "temperature": 85
  }
]
Try a fresh construction

This clears this draft, including its undo history. Earlier successful attempts stay recorded. Build again without opening hints to record an independent attempt.

Stuck? Inspect a worked construction

The tools below form one possible solution. You can assemble it, follow its signals, and undo that change to return to your own construction.

Assumptions and test precision

The browser runs an explicit model of the mechanism. It does not connect to MongoDB or Redis, simulate their query planners, or establish their concurrency guarantees. Numerical tests allow a difference of 0.001. Lists and structures must also have the right shape.

Your last tested pieces can start the full construction. An existing draft there keeps its own pieces.

The requested site has no index bucket

This check uses the pieces from “Find candidates before deciding which match”.

BOTIE

All supplied documents belong to west; the query asks for east. Predict the projected results even though west has a high temperature.
Current reading documents
[
  {
    "asset_id": "P8",
    "site": "west",
    "temperature": 99
  }
]
Requested site
east
Temperature threshold
80
No candidates
[]

Use a number, text, or an array matching the requested result. For a matrix, put each row in brackets. Saving your prediction runs your current construction on these inputs and checks the earlier examples too.

Build a construction in the workspace above first. This case will test those pieces.

If nearly every record belongs to north, what does using this bucket tell us about its practical speedup?

Measure candidates, remaining work and write cost on the real workload before claiming an index helps.

The browser runs an explicit model of the mechanism. It does not connect to MongoDB or Redis, simulate their query planners, or establish their concurrency guarantees.

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