Practice Mode • SQL & Data • easy

Latest Credential Version

100 points

Deduplicate credentials to their latest version.

Problem

You are implementing deduplicate credentials to their latest version. The input is one JSON value. Return exactly the JSON or scalar result described by the examples, with stable ordering and no extra logging. Deduplicate records by key, retaining the latest stable winner. Explain your reasoning and complexity during interview review; the judge evaluates only the returned result.

Input contract

One UTF-8 JSON value matching the structures shown in the examples.

Output contract

One deterministic JSON value or scalar with no explanatory text.

Target complexity

Partition/rank by key and descending time

Judge protocol

sql-fixture-json-v1

Examples

Example 1

Input: {"key":"entity","rows":[{"entity":"a","id":1,"time":1,"value":"old"},{"entity":"a","id":2,"time":2,"value":"new"},{"entity":"b","id":3,"time":1,"value":2}],"time":"time"}
Output: [{"entity":"a","id":2,"time":2,"value":"new"},{"entity":"b","id":3,"time":1,"value":2}]

This example demonstrates the core sql data invariant.

Example 2

Input: {"key":"entity","rows":[],"time":"time"}
Output: []

This example covers the empty or minimum boundary.

Constraints

Input is valid UTF-8 JSON and is at most 64 KB.
Output must be deterministic for identical input.
Do not use network access, persistent filesystem writes, subprocesses, or environment secrets.
Handle the empty or minimum boundary shown in the examples.

Progressive hints

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