stddev(value: numeric or duration) -> value

Computes the standard deviation of a numeric-or-duration column across each group (or window frame). Null inputs are skipped. numeric-typed inputs are cast through float64 for the statistical step to avoid overflow; for plain numeric inputs the result is typically float64, while duration-like inputs keep their kind.

Domain

This is an aggregate function (aggregates rows over a group in aggregate verbs).

This is a window function (calculates over a group of multiple input rows using windowing).

Categories

• Aggregate
• Numeric
• Time
• Window

Examples

statsby latency_jitter_ms:stddev(latency_ms), group_by(route)

Measures per-route spread of latency_ms with stddev so you can compare variability alongside mean latency.