Persistence

Purpose

Database storage, blob store, schema management, and concurrent access — the store layer.

Requirements

Requirement: TIA-STORE-001 — Embedded transactional database

The store SHALL persist the queryable index in an embedded transactional database.

Scenario: Embedded database

• GIVEN the store
• WHEN persisting the queryable index
• THEN it SHALL use an embedded transactional database (e.g. SQLite)

Requirement: TIA-STORE-002 — Content-addressed blob store

The store SHALL persist large per-run payloads in a content-addressed blob store, deduplicated by content hash.

Scenario: Deduplicated blob storage

• GIVEN a per-run payload
• WHEN it is persisted
• THEN it SHALL be stored in a content-addressed blob store
• AND duplicates SHALL be deduplicated by content hash

Requirement: TIA-STORE-003 — Export and import

The store SHALL support export and import of the dependency graph and provenance in a documented interchange format.

Scenario: Graph export

• GIVEN a populated store
• WHEN export is requested
• THEN the dependency graph and provenance SHALL be exported in a documented interchange format

Requirement: TIA-STORE-004 — Schema migration

When the store schema version differs from the running core, the core SHALL migrate or refuse with a clear diagnostic rather than corrupt data.

Scenario: Schema version mismatch

• GIVEN a store with an older schema version than the running core
• WHEN the core attempts to use it
• THEN the core SHALL either migrate the schema or refuse with a clear diagnostic
• AND SHALL NOT corrupt data

Requirement: TIA-STORE-005 — Concurrent reads during write

The store SHALL support concurrent reads during an in-progress write.

Scenario: Read during write

• GIVEN an in-progress write to the store
• WHEN a read request arrives
• THEN the store SHALL allow the read to proceed concurrently