0739 — Partial sweep grace applies to every batch

Context

0738 relaxed the eligibility cutoff after one batch, draining the entire TTL-expired prefix. The user chose to remove that special case. The grace benchmark executed no partial deletes, so it provides no evidence for that reset.

Decision

Supersede 0738 only in batch eligibility: every batch checks whether its oldest row is older than TTL plus grace. Stop when the next batch remains within grace. Keep the normal TTL predicate inside each eligible batch; a batch may therefore include expired rows still within grace. Grace is a batch gate, not a per-row minimum lifetime. Defaults, whole drops, cursor protection, and eventual sparse-partition cleanup remain unchanged.

Consequences

No cutoff reset or special first-batch behavior. Later batches can wait until their oldest row exceeds grace. Cleanup scheduling and consumer progress still affect actual removal time. Integration regression covers stopping at the deferred next batch and later removing overdue rows.