Search streaming pages terminal sealing and append-only ordering

• Status: Accepted
• Date: 2026-02-26
• Context:
  • Motivation: ERD acceptance item 586 requires streaming search behavior with early page emission, append-only ordering, and deterministic page sealing at terminal request state.
  • Constraints:
    • Runtime DB behavior must remain stored-procedure driven.
    • Search-page ordering must not reorder based on later score updates.
  • Dependency rationale:
    • No new dependencies were added.
    • Alternative considered: rely on API-layer finalization when runs complete. Rejected because sealing and terminal status must stay deterministic inside database state transitions.
• Decision:
  • Added migration 0095_search_request_terminal_seal.sql:
    • Creates trigger function search_request_finalize_on_runs_terminal_v1.
    • On indexer run terminal updates, finalizes search_request when no queued/running runs remain.
    • Seals any unsealed search_page rows at request finalization time.
  • Extended search_result_ingest integration coverage in crates/revaer-data/src/indexers/search_results.rs:
    • Added deterministic append-order streaming test across two pages with a late high-seeder result.
    • Added request-finished + page-sealed assertions after run completion.
• Consequences:
  • Positive outcomes:
    • Search requests now reach terminal status and sealed pages deterministically when runs complete.
    • Streaming append-only behavior is explicitly regression-tested.
  • Risks or trade-offs:
    • Trigger introduces additional write work during run terminal updates; scope is bounded to the affected request.
• Follow-up:
  • Test coverage summary:
    • Verified with just ci and just ui-e2e.
  • Observability updates:
    • No new telemetry fields were introduced.
  • Risk and rollback:
    • Rollback is isolated to migration 0095 and associated test/checklist/docs changes.
  • Review checkpoints:
    • Continue with next unchecked ERD acceptance item after 586.