Constant CURATED 

const CURATED: &[CuratedMetricSink];

The curated metric sinks, installed on every replica.

Sources take their measurements from the raw ..._raw logging relations, never from a derived view that re-aggregates them, like mz_dataflow_arrangement_sizes: those churn even on static data, and a per-dataflow size metric off the derived view measured ~30x the raw form. Cheap mapping views over the same logs, mz_dataflow_operator_dataflows and mz_compute_exports, carry no aggregation and are read freely.

Every family sums across workers, so a series carries no worker_id, and a multi-process replica reports one number per grouping key rather than one per process. The size families emit one series per dataflow, the errors family one per export.