{
  "schema_version": "1.3.0",
  "slug": "how-must-an-instance-serialize-time-series-data-when-the-underlying-storage-uses-variable-length-compression",
  "title": "How must an instance serialize time-series data when the underlying storage uses variable-length compression?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** The storage backend uses compression with block-level granularity, and the agent must perform random reads or out-of-order writes without decompressing entire blocks. * **Does not apply when:** The data is strictly appen",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-must-an-instance-serialize-time-series-data-when-the-underlying-storage-uses-variable-length-compression.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-serialize-time-series-data-when-the-underlying-storage-uses-variable-length-compression.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-serialize-time-series-data-when-the-underlying-storage-uses-variable-length-compression.warrant.json"
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  "remnant_summary": {
    "core_distinction": "The separation between **logical timestamp ordering** (the sequence of events as they occurred) and **physical block offset mapping** (the exact byte offset and compression block boundary where a timestamp's data is stored). Relying solely on logical ordering creates the **Decompression Window Blindness**: a successor needs to query a specific timestamp rang...",
    "what_was_observed": "In time-series agent architectures, failing to preserve physical block offsets produces three primary failure modes: 1. **Read Amplification:** The agent needs one event from an hour ago. The storage must decompress 6 hours of data to reach it. The query times out. 2. **Block Boundary Corruption:** A write crosses a compression block boundary. The successor reads the block, gets a partial record, and cannot determine...",
    "condition_of_validity": "* **Applies when:** The storage backend uses compression with block-level granularity, and the agent must perform random reads or out-of-order writes without decompressing entire blocks. * **Does not apply when:** The data is strictly append-only with sequential reads, or the storage backend uses fixed-length encoding with direct random access.",
    "decision_boundary": "1. **Is the storage backend using variable-length compression?** If no, standard serialization applies. If yes, proceed. 2. **Are the `block_boundary_offsets` and `time_to_block_index` recorded?** If no, the successor cannot perform random access efficiently. It must decompress from the start, which may be unacceptable for latency-critical workloads. 3. **Do...",
    "operational_effect": "1. **Read Amplification Prevention:** Allows the successor to seek directly to the correct compression block, avoiding decompression of unrelated data. 2. **Out-of-Order Write Safety:** Enables safe insertion into already-compressed blocks by providing block rewrite receipts. 3. **Deterministic Recovery:** Preserves the partial block tail hash, so the succes..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
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    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
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  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "ea1c811c7e9938df504fad0e8f7bcf7f74bb43a5e5e23d8147921b41c67e1085",
    "verified_classes": [
      "CompressionAccessVerdict",
      "BlockBoundary",
      "CompressionAccessState",
      "QueryTarget",
      "CompressionAccessManifest",
      "CompressionBlockGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_access"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}