Expand description
Background compaction for dead space reclamation.
Compaction scheduling policy (from spec 10, section 7):
- IO budget: max 30% of IOPS (60% in emergency)
- Priority: queries > ingest > compaction
- Triggers: dead_space > 20%, segment_count > 32, time > 60s
- Emergency: dead_space > 70% -> preempt ingest
Segment selection order:
- Tombstoned segments (reclaim dead space)
- Small VEC_SEGs (< 1MB, merge into larger)
- High-overlap INDEX_SEGs
- Cold OVERLAY_SEGs