nf.evidence.cdc

CDC Evidence Form (CDCEF)

Contract ID: nf.evidence.cdc | Family: evidence | Index Status: draft | AuthorityEffect: None

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1. Executive Summary & Metadata

CDC Evidence Form (CDCEF) enforces structural normalization and explicit defect routing in the evidence regime.

Property	Value
Canonical ID	nf.evidence.cdc
Short Name	CDCEF
Full Name	CDC Evidence Form
Family	evidence (Cryptographic Receipts, Dual Witnesses, Loss Ledgers, CDC Logs & Schema Totality)
Qualification	Extended Form Contract (Normal Form Contract)
Data / Math Posture	at_rest
Index Status	draft
Theory Status	proposed
Verification Status	absent
Contract Version	v0
Governance Fence	AuthorityEffect: None (certified_implies_authorized: false)

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2. Visual Architecture & Normalization Diagram

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3. Concrete Worked Example & Mechanism

Visual Transition Summary

Stage	Carrier / Operator	Concrete State / Invariant
1. Before / Candidate Input	Input Carrier (CDCEF Candidate)	Anomaly risk: uncertified write ; events
2. Normalization / Gate	CDCEF Verification Gate	every write event carries... (certified_implies_authorized: false)
3. After / Certified Output	Certified CDCEF Output	Invariant: ['old_row', 'new_row', ; 'changed_attributes', ; 'predicate_before_after',...

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4. The Four-Pillar Quadrilateral & Non-Claims

Every contract in simplex-normal-forms is evaluated against the Four-Pillar Quadrilateral defined in contracts/_golden_nfs/standard.yaml:

Pillar	Requirement	Contract Specification for nf.evidence.cdc
Pillar I: Excludes Anomaly	Name and eliminate a specific class of data or state defects.	uncertified write events
Pillar II: Preserves Invariant	State the structural invariant and protected skeleton preserved across transitions.	Invariant: every write event carries old row, new row, changed attributes, predicate membership, and group key before/after Protected Skeleton: ['old_row', 'new_row', 'changed_attributes', 'predicate_before_after', 'group_key_before_after']
Pillar III: Lossless Reconstruction	State the non-loss reconstruction operator (join, direct sum, pullback, or replay).	Lossless reconstruction under declared projection, direct sum, or pullback operators.
Pillar IV: Syntactic Decidability	State how conformance is decided from declared constraints without unbudgeted scans.	Decidable from declared schema and witness metadata within bounded evaluation budgets.

Explicit Non-Claims (certified_implies_authorized: false)

• does not ensure under declared assumptions physical disk-level ordering without a serializing verifier

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5. Operational Verification & Terminal Routing

5.1 Required Declarations

• relation_name
• write_timestamp
• changed_attributes

5.2 Required Evidence

• old_row_values
• new_row_values

5.3 Validation Criteria

Criterion ID	Name	Condition
criterion	Check	changed attributes are non-empty for updates
criterion	Check	group key changes must contain both before and after keys
criterion	Check	predicate transitions must declare prior and post states

5.4 Terminal Route Map

Every evaluation terminates in a declared local route mapped to a canonical terminal in standard.yaml:

Local Terminal Route	Canonical Terminal
EvidenceComplete	Preserve
EvidenceMissing	BudgetUnknown
Refuse	Refuse

5.5 Declared Failure Modes

• symptom: cache update attempted with missing status or customer ID columns in CDC event, diagnosis: uncertified write events, terminal: EvidenceMissing

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Deep-Dive Level Treatise

AuthorityEffect: None.
Level: Level 11 (Data in Motion / CDC Stream Compaction & Monotonicity)
Evidential Grade: NATIVE IMPLEMENTED
Contract Reference: nf.evidence.cdc
Mathematical Posture: Monotonic Stream Log Algebra & Tombstone Consistency
Data Posture: In Motion

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1. Schematic & Conceptual Architecture

Change Data Capture Normal Form (CDC-NF) disciplines event streams emitted by transaction logs:

• ensures under declared assumptions monotonic sequencing of log records via strict LSN / sequence numbers.
• Defines exact semantics for tombstone records during deletion.
• Formalizes log compaction: folding multiple updates to the same key into a single canonical delta without altering downstream observer convergence.

       Raw CDC Event Stream
  ┌──────┬────────┬────────┬─────────────────────────┐
  │ LSN  │ Key    │ Op     │ Payload                 │
  ├──────┼────────┼────────┼─────────────────────────┤
  │ 1001 │ Cust:5 │ INSERT │ {name: "Bob", bal: 100} │
  │ 1002 │ Cust:5 │ UPDATE │ {bal: 150}              │
  │ 1003 │ Cust:5 │ DELETE │ null (Tombstone)        │
  └──────┴────────┴────────┴─────────────────────────┘
                       │
             CDC-NF Stream Compaction
                       ▼
  Tombstone at LSN 1003 supersedes LSN 1001-1002.
  Compacted stream retains tombstone until epoch frontier clears!

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2. Mathematical Invariants & Quadrilateral Properties

1. Monotonicity & Total Ordering: Every event $e \in \mathcal{E}$ carries a sequence identifier $\operatorname{seq}(e)$ such that for any two events $e_1, e_2$ on key $K$: $$e_1 <_{\text{log}} e_2 \iff \operatorname{seq}(e_1) < \operatorname{seq}(e_2)$$

2. Compaction Operator $\odot$: For a stream segment $S_K = [e_1, \dots, e_m]$ on key $K$: $$\operatorname{compact}(S_K) = e_m \quad \text{if } e_m.\text{op} \in {\text{UPDATE}, \text{DELETE}}$$ with intermediate delta accumulation for commutative balance counters.

3. The Quadrilateral Invariants:

   • Anomaly Excluded: Out-of-order event replay, resurrecting deleted tuples via stale updates, unbounded log bloat.
   • Protected Skeleton: Entity keys, final state payloads, and tombstone sequence commitments.
   • Erased Structure: Overridden intermediate state transitions prior to the compaction frontier.
   • Reconstruction: Monotonic log replay matching point-in-time database snapshots.

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3. Terminal Routes & Verification Logic

CDC Event Stream & Invalidation Frontier
      │
      ├── Sequence strictly monotonic & tombstones valid ──► Preserve (StreamValid)
      │
      ├── Out-of-order sequence detected ──────────────────► Reject (MonotonicityViolation)
      │
      ├── Stale update arriving after tombstone ───────────► Refuse (ZombieUpdateRejected)
      │
      └── Uncompacted log exceeds retention ceiling ───────► Repair (CompactStream)

• Preserve: Stream adheres to monotonic sequence ensures under declared assumptions.
• Reject: Out-of-order delivery indicates broker or pipeline failure.
• Refuse: Event attempts to resurrect an explicitly deleted record.
• Repair: Safely compacts stream up to the active replication water mark.

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4. Test Evidence & Local Execution

Verified in test_bqnf_cdc_property.py:

• test_cdc_stream_monotonicity: Asserts that any decrement in LSN triggers immediate pipeline refusal.
• test_cdc_tombstone_compaction: Verifies that tombstone records correctly extinguish preceding insert/update deltas.

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5. Epistemic Claim Quadrant

1. What it supports:
   • Deterministic event sourcing and reproducible streaming database replication.
   • Formal ensures under declared assumptions against zombie row resurrection.
2. What it does not support:
   • Multi-writer conflict-free replication across partitioned networks (requires CRDT / distributed consensus).
3. The narrowest defensible claim:
   • CDC-NF ensures under declared assumptions that replay of the compacted stream yields the identical final state as the uncompacted stream.
4. The next test needed:
   • Property tests under randomized concurrent partition delays asserting that the tombstone water mark is monotonic.

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6. Epistemic Claim Hygiene Quadrant

In accordance with the repository's epistemic claim discipline:

1. What it supports:
   • Supports syntactic and operational checking of nf.evidence.cdc (CDCEF) against its declared schema, boundary constraints, and witness obligations in this model.
   • Supports deterministic terminal routing (EvidenceComplete, EvidenceMissing, Refuse) when required declarations or invariants fail.
2. What it does not support:
   • Does not confer operational authority (AuthorityEffect: None, certified_implies_authorized: false).
   • Does not claim semantic truth of undeclared external processes or unverified upstream inputs beyond the declaredprotected skeleton.
3. The narrowest defensible claim:
   • Within the declared substrate at_rest, this contract enforces that uncertified write events is either excluded under every write event carries old row, new row, changed attributes, predicate membership, and group key before/after or routed to an explicit refusal/recovery terminal.
4. The next test needed:
   • Property-based falsification and mutation testing across boundary edge cases and composed multi-step pipelines for nf.evidence.cdc.

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7. Canonical YAML Contract (contracts/nf.evidence.cdc.yaml)

Click to expand full canonical YAML contract (contracts/nf.evidence.cdc.yaml)

schema_version: smplx.nf.contract.v0
contract_kind: normal_form_contract
identity:
  id: nf.evidence.cdc
  name: CDC Evidence Form
  short_name: CDCEF
  version: v0
  status: draft
  family: evidence
  theory_status: proposed
  contract_status: draft
  verification_status: absent
classification:
  hierarchy_level: form
  subject_kind:
  - certificate_packet
  data_posture: at_rest
  mathematical_posture: operational
purpose:
  excludes_anomaly: uncertified write events
  preserves_invariant: every write event carries old row, new row, changed attributes,
    predicate membership, and group key before/after
  protected_skeleton:
  - old_row
  - new_row
  - changed_attributes
  - predicate_before_after
  - group_key_before_after
  erased_structure: []
  non_claims:
  - does not ensure under declared assumptions physical disk-level ordering without a serializing verifier
declarations_required:
- relation_name
- write_timestamp
- changed_attributes
evidence_required:
- old_row_values
- new_row_values
validation_criteria:
- changed attributes are non-empty for updates
- group key changes must contain both before and after keys
- predicate transitions must declare prior and post states
proof_obligations: []
terminal_routes:
- EvidenceComplete
- EvidenceMissing
- Refuse
certification:
  certificate_required: false
  certificate_kind: null
  obstruction_class_required: false
  loss_ledger_required: false
  verifier_required: true
authorization:
  authorized_by: null
  certified_implies_authorized: false
failure_modes:
- symptom: cache update attempted with missing status or customer ID columns in CDC
    event
  diagnosis: uncertified write events
  terminal: EvidenceMissing
references:
- ../1_normal_forms.md
- ../1a_bqnf_incremental_repair.md
terminal_route_map:
  EvidenceComplete: Preserve
  EvidenceMissing: BudgetUnknown
  Refuse: Refuse
definition:
  source: coda_all_universe/mssn_sn_tower/definitions.md
  formal_statement: uncertified write events. every write event carries old row, new
    row, changed attributes, predicate membership, and group key before/after
  quadrilateral:
    qualifies_as_true_normal_form: false
    qualification_gap: reconstruction_is_not_a_relational_project_join
    anomaly_exclusion: uncertified write events
    lossless_join:
      status: declared_reconstruction
      statement: every write event carries old row, new row, changed attributes, predicate
        membership, and group key before/after
    dependency_preservation:
      status: declared_with_the_invariant
      statement: The preserved invariant stays on the declared schema. This form does
        not state a functional-dependency projection of a flat relvar decomposition.
    syntactic_decision:
      status: declaration_decidable
      statement: The check reads the declared constraints and validation criteria.
        One unrecorded runtime image is not the decider.
schema_ref: ./normal_form_contract_schema.yaml