Backend & systems·Observability and operations
you wrap the database call in its own timed unit so it shows up as its own bar inside the request's waterfall.
Span
Also calledtrace span
One timed operation within a trace, with a start, a duration, a parent and attributes. Spans nest to form the trace. Span granularity is a real cost decision: per-function spans generate enormous volume, while per-service spans hide the slow part inside them.