Context

Phase 5 Community Detection (epic #1222, issue #1228) added delete_expired_edges which filters on expired_at.

Problem

Migration 021 creates indexes on source_entity_id, target_entity_id, valid_to (partial), name, entity_type, and last_seen_at. There is no index on graph_edges.expired_at. The eviction query performs a full table scan:

DELETE FROM graph_edges
WHERE expired_at IS NOT NULL
  AND expired_at < datetime('now', '-N days')

At 50K edges this is ~10ms (acceptable), but degrades with edge accumulation.

Suggested Fix

Add a follow-up migration:

CREATE INDEX idx_graph_edges_expired ON graph_edges(expired_at) WHERE expired_at IS NOT NULL;

Source

PERF-05 from Phase 5 performance analysis.