blue/.blue/dialogues/2026-02-06T1839Z-rfc-0058-supersession-hybrid-relational-dynamodb-architecture/round-2.summary.md

Round 2 Summary — Judge's Synthesis

What Round 2 Resolved

Round 2 resolved all 7 open tensions from Round 1 with zero or one new tension. The panel has converged on a concrete action plan.

The Converged Position

Do NOT supersede RFC 0058 with a hybrid architecture. Instead, amend the implementation sequence:

1. Phase A — Build the trait boundary first (RFC 0053)

   • Extract DialogueStore trait from 32 existing &Connection functions
   • Implement SqliteDialogueStore as the reference implementation
   • Convert dialogue.rs handler call sites
   • Exit gate: Zero bare pub fn ...(conn: &Connection) signatures in alignment_db.rs
   • Forced decisions: Which methods survive (CROISSANT R1-T01), domain-shaped trait (STRUDEL R1-T01)

2. Phase B — Define portable encryption envelope

   • AAD = sha256(canonical_entity_address) where canonical address is backend-independent
   • E.g., dialogue:{id}/entity:{type}/{subkey} — same string regardless of DynamoDB pk/sk or SQL columns
   • Exit gate: Envelope spec passes round-trip test across both backends
   • Must happen before first encrypted write (TARTLET R1-T01)

3. Phase C — Implement DynamoDB behind the trait (RFC 0058)

   • DynamoDialogueStore implements the stable trait
   • Full-partition load + in-memory graph assembly (no verdict denormalization)
   • DynamoDB Local integration tests pass the same generic test suite as SQLite
   • Exit gate: Dual-implementation CI passes

Key Design Decisions Converged

Decision	Resolution	Settled By
Hybrid architecture	Rejected	Near-unanimous (R0-R2)
Trait governance gate	ADR + PartitionScoped marker trait	Croissant
Trait shape	Domain access patterns (partition-scoped CRUD)	Croissant + Strudel
Verdict denormalization	Eliminated (in-memory assembly instead)	Cannoli + Muffin
Encryption portability	Canonical entity address for AAD	Tartlet
Implementation sequencing	Trait first, envelope second, DynamoDB third	Galette
Cross-partition queries	Separate AnalyticsStore trait	Croissant

One Remaining Disagreement

Refs table design — Strudel and Cannoli disagree on where edge data lives within the partition:

• Strudel: Entities already carry inline refs as JSON arrays. The refs table is a redundant SQLite artifact. Drop it.
• Cannoli: Keep refs as cleartext DynamoDB items. One item per edge, no encrypted payload to re-seal on mutation. Cheapest representation.

Both positions are compatible with the agreed read pattern (full-partition load + in-memory assembly). This is a schema implementation detail, not an architectural tension.

Strudel's Minor New Tension

Graph assembly belongs in a shared library, not a trait method. If the trait exposes fn get_verdict_with_context(...), every backend must independently implement graph assembly. If instead the trait returns raw entities and a shared library assembles the graph, the trait stays thin. Croissant's response addresses this: trait returns domain types, assembly logic lives in the shared layer above the trait.

Convergence Assessment

Metric	R0	R1	R2
Open Tensions	10	7	1 (minor)
New Perspectives	20	9	3
Velocity	30	16	4
Converge %	0%	0%	~83%

Velocity has dropped from 30 → 16 → 4. Five of six experts raised zero new tensions. The dialogue is ready for a convergence round.