metric,precompute,single_or,note
page1_unified_parents,20,20,keyset page — both parent paths return the same 20
page1_unified_rows,60,60,LATERAL top-3 per parent (<=60)
page1_buffers_shared_hit,63,181,env-dependent (relative only — warm cache)
deep_keyset_parent_scanned,19,200,precompute index-range(19) vs BitmapOr + hashed mention SubPlan(200)
deep_keyset_buffers_shared_hit,60,88,env-dependent (relative only — warm cache)
viewer_visible_set,1500,1500,feed_visible count for user008 (= single-OR page-1 candidate set)