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

Accumulated Tensions

RESOLVED

MACARON-T01 (R0): No rollback plan if hybrid migration stalls

Resolved in R1 by Macaron: RFC 0053's single-active-backend factory pattern provides the rollback mechanism — revert the config, keep SQLite as fallback, no split-brain.

BRIOCHE-T01 (R0): Operational simplicity vs analytical query flexibility

Resolved in R1 by Muffin's concession: Cross-dialogue analytics is speculative and violates YAGNI. Withdrawn as justification for hybrid.

STRUDEL-T01 (R0): Event-sourced schema redesign vs sunk-cost commitment to RFC 0051

Narrowed in R1 by Strudel: Full event-sourcing is disproportionate. Only the refs table needs redesign. The other 13 entity types map cleanly to DynamoDB. Subsumed by STRUDEL R1-T01.

PARTIALLY ADDRESSED

SCONE-T01 (R0): RFC 0051 schema strains single-table DynamoDB design

Partially addressed by Strudel's scoping: only the refs table is the genuine mismatch. The other 13 entity types fit DynamoDB's partition-scoped model. Status: NARROWED — tension reduced to refs table specifically

ECLAIR-T01 (R0): Local-prod parity vs query model fitness

Partially addressed by Cannoli: parity requires a single code path, not DynamoDB specifically. Eclair refined: parity doesn't require DynamoDB. Status: NARROWED — reduced to deployment target question (serverless vs containerized)

CANNOLI-T01 (R0): Serverless deployment constraints vs relational query expressiveness

Partially addressed by Cannoli R1: RFC 0058's architecture implicitly targets serverless. Panel should treat serverless as baseline. Status: PARTIALLY RESOLVED — serverless baseline implied but not formally established

DONUT-T01 (R0): Scale threshold undefined

Partially addressed by Tartlet's concession: at sub-10K dialogues, DynamoDB query cost premium is negligible. Cost is not a decision driver. Status: PARTIALLY RESOLVED — cost argument neutralized, but volume assumptions unstated

CUPCAKE-T01 (R0): Unbounded future query patterns vs locked access patterns

Status: OPEN — no R1 expert addressed this directly. Muffin withdrew the analytics argument but the general question remains.

CROISSANT-T01 (R0): Trait completeness vs leaky abstraction risk

Refined in R1 by Croissant into CROISSANT R1-T01. The abstract risk is now concrete: trait method governance. Status: SUPERSEDED by CROISSANT R1-T01

MUFFIN-T01 (R0): Denormalized verdict fields prove graph too expensive in DynamoDB

Evolved in R1 into MUFFIN R1-T01 (consistency risk) and ECLAIR R1-T01 (domain model leakage). Status: SUPERSEDED by MUFFIN R1-T01 and ECLAIR R1-T01

OPEN — Round 1 Tensions

Cluster D: Trait Governance & Shape (2 tensions)

CROISSANT R1-T01: Trait method governance gap

No RFC or ADR governs what methods may be added to DialogueStore. Without a review gate requiring each new method to demonstrate O(1)-partition-read implementability on DynamoDB, the trait will accumulate relational-only methods and silently make the DynamoDB backend unviable. Status: OPEN — actionable, needs concrete gate proposal

STRUDEL R1-T01: Trait-shaped-by-workarounds vs trait-shaped-by-domain

Should the DialogueStore trait be designed from domain access patterns (backend-neutral) or from the DynamoDB implementation experience (which leaks GSI-shaped query methods)? Status: OPEN — design philosophy question

Cluster E: Denormalization Consequences (3 tensions)

MUFFIN R1-T01: Verdict denormalization consistency risk

If a recommendation is adopted by a verdict and later a new tension is linked to that recommendation, the verdict's pre-computed arrays are stale. RFC 0058 specifies no consistency mechanism. Status: OPEN — correctness risk, needs solution

ECLAIR R1-T01: Denormalization artifacts leak through trait into domain model

DynamoDB-specific denormalized fields (verdict arrays, pre-computed ref chains) exist in the domain model, not behind the trait. A future backend swap would require maintaining dead denormalization logic or a second schema migration. Status: OPEN — architectural concern

MACARON R1-T01: Denormalization cost unmeasured

Write-amplification concern on verdict denormalization is valid in theory but nobody has measured: with ~10-20 verdicts per dialogue, the amplification is bounded and small. Status: OPEN — needs quantification

Cluster F: Migration & Encryption (1 tension)

TARTLET R1-T01: Encryption envelope portability unspecified

Neither RFC 0053 nor RFC 0058 defines whether the AES-256-GCM envelope format, AAD binding (which includes pk||sk), and hash chain structure are backend-portable or implicitly coupled to DynamoDB's key structure. Status: OPEN — critical gap, blocks future backend portability

Cluster G: Prerequisites (1 tension)

GALETTE R1-T01: Prerequisite inversion

RFC 0053's trait boundary does not exist in the codebase. alignment_db.rs has 30+ direct rusqlite::Connection call sites with zero trait indirection. The supersession debate is premature until this foundation is built. Status: OPEN — sequencing problem, affects all other decisions

Tension Summary

Category	R0 Open	R0 Resolved	R1 New	R1 Total Open
Schema-Storage Mismatch	5	1 narrowed, 2 superseded	—	1 (narrowed)
Operational & Deployment	3	2 resolved	—	1 (partial)
Cost & Scale	2	—	—	1 (partial)
Trait Governance & Shape	—	—	2	2
Denormalization Consequences	—	—	3	3
Migration & Encryption	—	—	1	1
Prerequisites	—	—	1	1
Total	10	3 resolved, 2 superseded	7	7 open + 3 partial