The wait profile of a PostgreSQL analysis pass: Lock, LWLock, IO and IPC rollups with their named standouts as fractions of the wait source's own observed time — Aurora's measured deltas under the three-state interval, or stock's sampling estimate marked is_sampled with its resolution and read only when the Aurora table is empty — so a PostgreSQL operator learns which wait class a backend-equivalent of time is going to, at which evidence grade, and what PostgreSQL's own levers for it are (#3542 lane 5) - #3683