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Merge join matches only the first row of a repeated right key · case 02

Merge join matches only the first row of a repeated right key.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Join two key-sorted non-null relations [key,id] by matching equal-key runs. Emit the full left-major Cartesian product for each matching run. Advance the lower unmatched run and preserve physical order within equal-key runs.

Why this case matters

A bounded deterministic data engine model makes representation and changelog faults reproducible.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
duplicate runs	`[[10, 20], [11, 20]]`	`[[10, 20], [10, 21], [11, 20], [11, 21]]`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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