Failure Modes
PreFlight — Deterministic Upstream Data Ingestion Gate
pf_v1.01 detects the seven failure modes documented on this page, at the ingestion boundary, before execution.
Failure Classification
Failure is a deterministic enforcement outcome indicating that ingestion safety cannot be mechanically verified.
- A structural boundary verdict
- A consequence of provable ingestion risk
- Not a runtime error
PreFlight enforces structural safety only.
1. Schema Structural Integrity
Failure occurs when column structure cannot be deterministically aligned across records.
- Column count mismatch
- Row-level structural inconsistency
- Structural drift across records
- Column misalignment under the resolved delimiter
Structural integrity is a prerequisite for ingestion safety.
See this failure in the Evidence →
2. Row Iteration Viability
Failure occurs when dataset rows cannot be deterministically traversed.
- Corrupted record boundaries
- Malformed row termination
- Truncated structural segments
- Non-iterable record sequences
If rows cannot be traversed deterministically, ingestion safety cannot be verified.
See this failure in the Evidence →
3. Numeric Coercibility
Failure occurs when declared numeric fields contain non-coercible or structurally invalid values.
- Mixed numeric and non-numeric tokens
- Irreversible coercion states
- Invalid numeric encoding
Declared numeric context must remain structurally stable.
See this failure in the Evidence →
4. Multiple Valid Representations
Exposure occurs when a field supports more than one structurally valid representation without corruption.
- Mixed timestamp formats
- Mixed numeric encodings
- Alternative structural representations within a single field
This condition may reduce to WARN when structural exposure exists without deterministic failure.
See this failure in the Evidence →
5. High Null Density Columns
Exposure occurs when declared fields exhibit structurally significant null concentration.
- Predominantly null columns
- Null behavior outside declared tolerance
Null concentration may introduce ingestion exposure without corruption.
See this failure in the Evidence →
6. Malformed or Truncated Rows
Failure occurs when record continuity or dataset termination cannot be deterministically confirmed.
- Incomplete trailing records
- Partial structural fragments
- File boundary corruption
Structural continuity is required for ingestion safety.
See this failure in the Evidence →
7. Text Encoding Integrity
Failure occurs when character encoding prevents deterministic parsing.
- Non-decodable byte sequences
- Encoding ambiguity
- Structural corruption introduced by invalid byte states
Parsing determinism must remain intact.
See this failure in the Evidence →
Reduction rules and evaluability thresholds: Contract. Guarantees: Guarantees.