LoadSealPastLine	crates/backend/access/pgrcolumnar/pgrc_write/src/par.rs	ladder_gate	isojoin	D4365,D4370	a parallel COPY into pgrcolumnar whose part's seal reserve (3x its normalized bytes) stays past the memory ladder's line after its climb, R5 wait and one hand-off is refused, where an early seal or a column-at-a-time streaming seal would fit it (D4370; user ruling via main 2026-10-13: COPY into pgrc is spill debt until it can spill)	bulk load	A COPY into a pgrcolumnar table seals each part it writes in memory, at about three times the part's size, where it cannot yet write that part out in pieces, so when the server has no more memory to give it the statement fails with an out-of-memory error instead of finishing more slowly.
