PromQL Essentials: Practical Query Patterns

Instant Vectors vs Range Vectors#

An instant vector returns one sample per time series at a single point in time. A range vector returns multiple samples per time series over a time window.

# Instant vector: current value of each series
http_requests_total{job="api"}

# Range vector: last 5 minutes of samples for each series
http_requests_total{job="api"}[5m]

You cannot graph a range vector directly. Functions like rate() and increase() consume a range vector and return an instant vector, which Grafana can then plot.