pub fn validate_metric_sink_prefix(prefix: &str) -> Result<(), PlanError>Expand description
Rejects a prefix that is not a legal start of a Prometheus metric name, or that escapes the
reserved mz_metric_sink_ lane (METRIC_SINK_PREFIX_MARKER). The reserved leading character
is what lets a row’s bare metric_name start with a digit or be empty. User sinks use
validate_user_metric_sink_prefix, which adds the curated reservation.