{
  "schema_version": 1,
  "evidence_type": "executed synthetic operations",
  "command": "python operations.py",
  "passed": true,
  "checks": [
    {
      "id": "backfill-after-commit",
      "description": "Resume actual recipe after process death",
      "expected": "750 committed rows retained; uncommitted batch absent; 4250 rows resume; integrity ok",
      "observed": {
        "persisted_rows": 750,
        "persisted_checkpoint": 750,
        "resume_rows": 4250,
        "integrity": "ok",
        "kill_boundary": {
          "mode": "backfill-after-commit",
          "boundary": "after-third-commit",
          "checkpoint": 750
        }
      },
      "passed": true,
      "method": "real SIGKILL at transaction boundary"
    },
    {
      "id": "backfill-before-commit",
      "description": "Resume actual recipe after process death",
      "expected": "750 committed rows retained; uncommitted batch absent; 4250 rows resume; integrity ok",
      "observed": {
        "persisted_rows": 750,
        "persisted_checkpoint": 750,
        "resume_rows": 4250,
        "integrity": "ok",
        "kill_boundary": {
          "mode": "backfill-before-commit",
          "boundary": "transaction-written-before-commit",
          "checkpoint": 1000
        }
      },
      "passed": true,
      "method": "real SIGKILL at transaction boundary"
    },
    {
      "id": "contract-before-commit",
      "description": "Resume actual recipe after process death",
      "expected": "pre-contract schema and triggers restored; clean retry contracts",
      "observed": {
        "recovered_stage": "cutover",
        "legacy_tag_present": true,
        "integrity": "ok",
        "kill_boundary": {
          "mode": "contract-before-commit",
          "boundary": "transaction-written-before-commit",
          "checkpoint": 5000
        }
      },
      "passed": true,
      "method": "real SIGKILL at transaction boundary"
    },
    {
      "id": "overlap-traffic",
      "description": "Preserve old-application writes during migration",
      "expected": "100 updates and 100 inserts retained; both contracts agree",
      "observed": {
        "writer_commits": 100,
        "writer_errors": [],
        "rows": 20100,
        "normalized_updates": 100,
        "missing_keys": 0,
        "contracts_agree": true
      },
      "passed": true,
      "method": "two SQLite connections with a writer thread"
    },
    {
      "id": "forward-recovery",
      "description": "Recover removed source tags without losing newer content",
      "expected": "exact original tags and post-contract description retained",
      "observed": {
        "archived_rows": 20100,
        "archive_sha256": "e3cffd9a88fd5d81f2701d07b5a9c99aa7886f9d04c6019736a8f57cb8869e9c",
        "restored_sha256": "e3cffd9a88fd5d81f2701d07b5a9c99aa7886f9d04c6019736a8f57cb8869e9c",
        "newer_content_preserved": true
      },
      "passed": true,
      "method": "executed forward schema change using pre-contract archive"
    },
    {
      "id": "lock-abort-retry",
      "description": "Timeout leaves the schema unchanged and a later attempt succeeds",
      "expected": "locked error; legacy schema retained; retry expands",
      "observed": {
        "error": "database is locked",
        "observed_wait_seconds": 0.075993,
        "timeout_seconds": 0.075,
        "unchanged_on_timeout": true,
        "retry_succeeded": true
      },
      "passed": true,
      "method": "real SQLite held write transaction"
    },
    {
      "id": "size-and-batch-sweep",
      "description": "Preserve contents across fixture size and batch sizes",
      "expected": "all row counts, content digests and integrity checks match",
      "observed": {
        "cases": 5,
        "largest_rows": 100000,
        "all_preserved": true
      },
      "passed": true,
      "method": "five executed SQLite rollouts"
    },
    {
      "id": "postgres-lock-model",
      "description": "Evaluate DDL/index contention under declared PostgreSQL lock modes",
      "expected": "DDL times out; regular index waits; concurrent index admits writer; concurrent builders conflict",
      "observed": {
        "modeled_cases": 4,
        "matched": 4
      },
      "passed": true,
      "method": "theoretical lock compatibility and timeline model"
    },
    {
      "id": "postgres-invalid-index-model",
      "description": "Block cutover until a repaired concurrent index is valid",
      "expected": "invalid named index blocks cutover; rebuild becomes valid",
      "observed": {
        "cutover_allowed_after_failure": false,
        "cutover_allowed_after_validated_retry": true
      },
      "passed": true,
      "method": "theoretical failed-build/catalog/retry state model"
    },
    {
      "id": "postgres-stage-boundary",
      "description": "Keep concurrent index creation outside a transaction block",
      "expected": "concurrent index stage is standalone",
      "observed": [
        {
          "stage": "expand",
          "transaction": true
        },
        {
          "stage": "backfill_batch",
          "transaction": true
        },
        {
          "stage": "create_index_concurrently",
          "transaction": false
        },
        {
          "stage": "validate_index",
          "transaction": true
        },
        {
          "stage": "contract",
          "transaction": true
        }
      ],
      "passed": true,
      "method": "theoretical executor schedule"
    }
  ],
  "source_sha256": {
    "operations.py": "045d26e31b4426f34671de0d07248059ddda6147ecd7e92e3a1a83b2d40b90aa",
    "rehearse.py": "70306b96c656828b14ec18bec0b76d02a0b25abadde97cc3d8958e3a97b78954"
  },
  "report": "operations-report.html",
  "limitations": [
    "Crash tests kill the Python process on Linux while SQLite retains normal filesystem and kernel behavior. They do not simulate power loss, torn sectors or storage-controller failures.",
    "PostgreSQL lock and failed-index cases are deterministic theoretical state models informed by PostgreSQL documentation, not measured PostgreSQL sessions.",
    "The concurrent writer is a synthetic workload over one asset table. No child-table migration, service discovery or live customer traffic is claimed.",
    "The original tag is recovered by an executed forward migration from an exact pre-contract tag archive. Without that archive, capitalization and whitespace cannot be reconstructed.",
    "Local sizes and timings are observations of this environment, not production capacity or downtime guarantees."
  ],
  "runtime": {
    "python": "3.12.14",
    "sqlite": "3.53.1",
    "platform": "Linux"
  },
  "observations": {
    "size_sweep": [
      {
        "rows": 5000,
        "batch_rows": 100,
        "seconds": 0.059222,
        "rows_per_second_observed": 84428.8,
        "database_and_wal_bytes": 2013056,
        "content_preserved": true,
        "committed_batches": 50
      },
      {
        "rows": 5000,
        "batch_rows": 1000,
        "seconds": 0.02121,
        "rows_per_second_observed": 235742.0,
        "database_and_wal_bytes": 1172576,
        "content_preserved": true,
        "committed_batches": 5
      },
      {
        "rows": 50000,
        "batch_rows": 100,
        "seconds": 0.881005,
        "rows_per_second_observed": 56753.4,
        "database_and_wal_bytes": 12307128,
        "content_preserved": true,
        "committed_batches": 500
      },
      {
        "rows": 50000,
        "batch_rows": 1000,
        "seconds": 0.288573,
        "rows_per_second_observed": 173266.6,
        "database_and_wal_bytes": 12212368,
        "content_preserved": true,
        "committed_batches": 50
      },
      {
        "rows": 100000,
        "batch_rows": 1000,
        "seconds": 0.671821,
        "rows_per_second_observed": 148849.1,
        "database_and_wal_bytes": 24696312,
        "content_preserved": true,
        "committed_batches": 100
      }
    ],
    "postgresql_lock_model": [
      {
        "scenario": "ddl-reader",
        "held": "AccessShare",
        "requested": "AccessExclusive",
        "holder_release_s": 2.0,
        "lock_timeout_s": 0.25,
        "modeled_wait_s": 0.25,
        "outcome": "timeout",
        "expected": "timeout"
      },
      {
        "scenario": "index-writer",
        "held": "RowExclusive",
        "requested": "Share",
        "holder_release_s": 0.8,
        "lock_timeout_s": 2.0,
        "modeled_wait_s": 0.8,
        "outcome": "granted_after_wait",
        "expected": "granted_after_wait"
      },
      {
        "scenario": "concurrent-index-writer",
        "held": "RowExclusive",
        "requested": "ShareUpdateExclusive",
        "holder_release_s": 0.8,
        "lock_timeout_s": 0.25,
        "modeled_wait_s": 0,
        "outcome": "granted",
        "expected": "granted"
      },
      {
        "scenario": "two-index-builds",
        "held": "ShareUpdateExclusive",
        "requested": "ShareUpdateExclusive",
        "holder_release_s": 2.0,
        "lock_timeout_s": 0.25,
        "modeled_wait_s": 0.25,
        "outcome": "timeout",
        "expected": "timeout"
      }
    ],
    "postgresql_index_model": [
      {
        "action": "start_build",
        "exists": true,
        "valid": false,
        "release_allowed": false
      },
      {
        "action": "duplicate_detected",
        "exists": true,
        "valid": false,
        "release_allowed": false
      },
      {
        "action": "inspect_catalog",
        "exists": true,
        "valid": false,
        "release_allowed": false
      },
      {
        "action": "drop_invalid",
        "exists": false,
        "valid": false,
        "release_allowed": false
      },
      {
        "action": "repair_fixture",
        "exists": false,
        "valid": false,
        "release_allowed": false
      },
      {
        "action": "retry_build",
        "exists": true,
        "valid": true,
        "release_allowed": false
      },
      {
        "action": "validate_catalog",
        "exists": true,
        "valid": true,
        "release_allowed": true
      }
    ],
    "postgresql_stage_plan": [
      {
        "stage": "expand",
        "transaction": true
      },
      {
        "stage": "backfill_batch",
        "transaction": true
      },
      {
        "stage": "create_index_concurrently",
        "transaction": false
      },
      {
        "stage": "validate_index",
        "transaction": true
      },
      {
        "stage": "contract",
        "transaction": true
      }
    ]
  },
  "seconds": 3.534596
}