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.