promql

Overview ¶

Package promql is an optional adapter that bridges the storage fetch contract (query/fetch) to the Prometheus storage.Queryable interface. It does not own a PromQL engine: the embedder (e.g. go-faster/oteldb, which already has PromQL/LogQL/TraceQL engines) drives its own promql.Engine over the Queryable this package returns. The storage library proper stops at the fetch seam and stays language- and Prometheus-free; this package is the only one importing github.com/prometheus/prometheus, and importing it is opt-in.

Condition extraction lives here (the language layer), never in storage: a Prometheus matcher that can match the empty string (e.g. `!=`, `!~`, `=""`) would wrongly exclude series that lack the label if pushed into the postings index, so only index-safe matchers are pushed down; every returned series is then re-checked against the full matcher set.