FA-129 / Storage and queries / Member archive

A snapshot read selects a version committed after its cutoff · case 04

A read returns the newest physical version even though that version was not visible at the reader's snapshot.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Versions are [key,commit_sequence,value], with integer commit sequences unique within a key. Return a map from key to the value at its greatest sequence <= cutoff; omit keys with no visible version. Input storage order is arbitrary.

Why this case matters

A deterministic committed-version visibility model for snapshot reads. It deliberately omits uncommitted transactions, transaction-ID wraparound, write conflict detection and real engine concurrency.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
future committed version is invisible	`{"a": "future"}`	`{"a": "seen"}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

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

Member access is invitation-based. Sign in with your invited account to inspect the sources.