FA-45746 / Data systems / Open access
Temporal enrichment exposes the hidden payload of a deleted dimension row · case 01
Temporal enrichment exposes the hidden payload of a deleted dimension row.
ROOT CAUSE
temporal-dimension-lookup: Temporal enrichment exposes the hidden payload of a deleted dimension row.
THE FAILURE
temporal-dimension-lookup: Temporal enrichment exposes the hidden payload of a deleted dimension row.
Unsuccessful approach: Replacing an absent tombstone payload with zero still revives a deleted value.
Case contract
Enrich facts [id,key,event-time] from versioned dimension rows [key,valid-from,revision,payload,tombstone]. For matching non-null key, use the greatest (valid-from,revision) no later than fact time. A selected tombstone yields None and blocks fallback to older versions. Emit [fact-id,payload-or-None].
Why this case matters
A bounded deterministic data engine model makes representation and changelog faults reproducible.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(d):
try:
facts,versions=d
out=[]
for ident,key,time in facts:
candidates=[r for r in versions if key is not None and r[0]==key and r[1]<=time]
if not candidates: out.append([ident,None]); continue
chosen=max(candidates,key=lambda r:(r[1],r[2]))
out.append([ident,chosen[3]])
return out
except (IndexError, KeyError, ValueError, StopIteration) as exc:
return {"representation_error": type(exc).__name__}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
check('future ignored', solve([[[10, 'a', 2]], [['a', 1, 1, 'old', False], ['a', 3, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 1]], [['a', 1, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 1]], [['a', 1, 1, 'old', False], ['a', 1, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 2]], [['a', 1, 1, 'old', False], ['a', 2, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 1]], [['a', 1, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 2]], [['a', 1, 1, 'right', False], ['b', 2, 1, 'wrong', False], [None, 2, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 1]], []]), [[10, None]])
elif N == 2:
check('future ignored', solve([[[10, 'a', 3]], [['a', 2, 1, 'old', False], ['a', 4, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 2]], [['a', 2, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 2]], [['a', 2, 1, 'old', False], ['a', 2, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 3]], [['a', 2, 1, 'old', False], ['a', 3, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 2]], [['a', 2, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 3]], [['a', 2, 1, 'right', False], ['b', 3, 1, 'wrong', False], [None, 3, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 2]], []]), [[10, None]])
elif N == 3:
check('future ignored', solve([[[10, 'a', 4]], [['a', 3, 1, 'old', False], ['a', 5, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 3]], [['a', 3, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 3]], [['a', 3, 1, 'old', False], ['a', 3, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 4]], [['a', 3, 1, 'old', False], ['a', 4, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 3]], [['a', 3, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 4]], [['a', 3, 1, 'right', False], ['b', 4, 1, 'wrong', False], [None, 4, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 3]], []]), [[10, None]])
elif N == 4:
check('future ignored', solve([[[10, 'a', 5]], [['a', 4, 1, 'old', False], ['a', 6, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 4]], [['a', 4, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 4]], [['a', 4, 1, 'old', False], ['a', 4, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 5]], [['a', 4, 1, 'old', False], ['a', 5, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 4]], [['a', 4, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 5]], [['a', 4, 1, 'right', False], ['b', 5, 1, 'wrong', False], [None, 5, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 4]], []]), [[10, None]])
elif N == 5:
check('future ignored', solve([[[10, 'a', 6]], [['a', 5, 1, 'old', False], ['a', 7, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 5]], [['a', 5, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 5]], [['a', 5, 1, 'old', False], ['a', 5, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 6]], [['a', 5, 1, 'old', False], ['a', 6, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 5]], [['a', 5, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 6]], [['a', 5, 1, 'right', False], ['b', 6, 1, 'wrong', False], [None, 6, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 5]], []]), [[10, None]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| future ignored | [[10, 'old']] | [[10, 'old']] | Passed |
| exact effective time | [[10, 'current']] | [[10, 'current']] | Passed |
| revision precedence | [[10, 'new']] | [[10, 'new']] | Passed |
| tombstone blocks old | [[10, None]] | [[10, None]] | Passed |
| tombstone hidden payload | [[10, 'hidden']] | [[10, None]] | Failed |
| other key | [[10, 'right']] | [[10, 'right']] | Passed |
| absent dimension | [[10, None]] | [[10, None]] | Passed |
SHA-256 / 91f02d873525bfc2d0930d1bd7058a10f42d0048e58be12fd5502de3137034b3
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(d):
try:
facts,versions=d
out=[]
for ident,key,time in facts:
candidates=[r for r in versions if key is not None and r[0]==key and r[1]<=time]
if not candidates: out.append([ident,None]); continue
chosen=max(candidates,key=lambda r:(r[1],r[2]))
out.append([ident,chosen[3] if chosen[3] is not None else 0])
return out
except (IndexError, KeyError, ValueError, StopIteration) as exc:
return {"representation_error": type(exc).__name__}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
check('future ignored', solve([[[10, 'a', 2]], [['a', 1, 1, 'old', False], ['a', 3, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 1]], [['a', 1, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 1]], [['a', 1, 1, 'old', False], ['a', 1, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 2]], [['a', 1, 1, 'old', False], ['a', 2, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 1]], [['a', 1, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 2]], [['a', 1, 1, 'right', False], ['b', 2, 1, 'wrong', False], [None, 2, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 1]], []]), [[10, None]])
elif N == 2:
check('future ignored', solve([[[10, 'a', 3]], [['a', 2, 1, 'old', False], ['a', 4, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 2]], [['a', 2, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 2]], [['a', 2, 1, 'old', False], ['a', 2, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 3]], [['a', 2, 1, 'old', False], ['a', 3, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 2]], [['a', 2, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 3]], [['a', 2, 1, 'right', False], ['b', 3, 1, 'wrong', False], [None, 3, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 2]], []]), [[10, None]])
elif N == 3:
check('future ignored', solve([[[10, 'a', 4]], [['a', 3, 1, 'old', False], ['a', 5, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 3]], [['a', 3, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 3]], [['a', 3, 1, 'old', False], ['a', 3, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 4]], [['a', 3, 1, 'old', False], ['a', 4, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 3]], [['a', 3, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 4]], [['a', 3, 1, 'right', False], ['b', 4, 1, 'wrong', False], [None, 4, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 3]], []]), [[10, None]])
elif N == 4:
check('future ignored', solve([[[10, 'a', 5]], [['a', 4, 1, 'old', False], ['a', 6, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 4]], [['a', 4, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 4]], [['a', 4, 1, 'old', False], ['a', 4, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 5]], [['a', 4, 1, 'old', False], ['a', 5, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 4]], [['a', 4, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 5]], [['a', 4, 1, 'right', False], ['b', 5, 1, 'wrong', False], [None, 5, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 4]], []]), [[10, None]])
elif N == 5:
check('future ignored', solve([[[10, 'a', 6]], [['a', 5, 1, 'old', False], ['a', 7, 1, 'future', False]]]), [[10, 'old']])
check('exact effective time', solve([[[10, 'a', 5]], [['a', 5, 1, 'current', False]]]), [[10, 'current']])
check('revision precedence', solve([[[10, 'a', 5]], [['a', 5, 1, 'old', False], ['a', 5, 2, 'new', False]]]), [[10, 'new']])
check('tombstone blocks old', solve([[[10, 'a', 6]], [['a', 5, 1, 'old', False], ['a', 6, 1, None, True]]]), [[10, None]])
check('tombstone hidden payload', solve([[[10, 'a', 5]], [['a', 5, 1, 'hidden', True]]]), [[10, None]])
check('other key', solve([[[10, 'a', 6]], [['a', 5, 1, 'right', False], ['b', 6, 1, 'wrong', False], [None, 6, 2, 'wildcard', False]]]), [[10, 'right']])
check('absent dimension', solve([[[10, 'a', 5]], []]), [[10, None]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| future ignored | [[10, 'old']] | [[10, 'old']] | Passed |
| exact effective time | [[10, 'current']] | [[10, 'current']] | Passed |
| revision precedence | [[10, 'new']] | [[10, 'new']] | Passed |
| tombstone blocks old | [[10, 0]] | [[10, None]] | Failed |
| tombstone hidden payload | [[10, 'hidden']] | [[10, None]] | Failed |
| other key | [[10, 'right']] | [[10, 'right']] | Passed |
| absent dimension | [[10, None]] | [[10, None]] | Passed |
SHA-256 / 52a8769b085b578451fe5866fa523ef950ce3b4f443adb03cedd7dc25d9bd108
HELD IN THE MEMBER ARCHIVE
The verified repair and its recorded checks are member-only.
This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.
Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.
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Sign in to the archive ↗Verification & scope
Offline stipulated semantics over valid small inputs; no performance, concurrency, or production-engine conformance claim. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:44:25.320112+00:00.
Case digest / e3492fed98c06ab680679e587a7e2655233ea9453ee057f4d5ee4a2212f502f0