ArmsNotOneRun	crates/gravity/lowerv4/src/ops/hashjoin/spill/build.rs	eligible_why	lifetime	D2084	a union-probed build whose arms are not one run with one marker each (nested markers, D1387) stays resident; since D4275 the build records it, read from the graph, as each arm's pair does	hash join	A hash join whose probe side is a UNION ALL nested inside another one that PostgreSQL does not flatten keeps its whole hash table in memory where PostgreSQL would spill it to disk, so the statement fails with an out-of-memory error when the server has no more memory to give it.
