From 87d7710c8e7dceeb8ce6d100cf84c85099fb5fd7 Mon Sep 17 00:00:00 2001 From: Aliaksandr Valialkin Date: Fri, 7 Aug 2020 07:50:15 +0300 Subject: [PATCH] docs/MetricsQL.md: mention that MetricsQL removes all the NaN values from results --- docs/MetricsQL.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/docs/MetricsQL.md b/docs/MetricsQL.md index b839b0d5d1..904afae6a2 100644 --- a/docs/MetricsQL.md +++ b/docs/MetricsQL.md @@ -12,6 +12,9 @@ The following functionality is implemented differently in MetricsQL comparing to * MetricsQL returns the expected non-empty responses for requests with `step` values smaller than scrape interval. This addresses [this issue from Grafana](https://github.com/grafana/grafana/issues/11451). * MetricsQL treats `scalar` type the same as `instant vector` without labels, since subtle difference between these types usually confuses users. See [the corresponding Prometheus docs](https://prometheus.io/docs/prometheus/latest/querying/basics/#expression-language-data-types) for details. +* MetricsQL removes all the `NaN` values from the output, so some queries like `(-1)^0.5` return empty results in VictoriaMetrics, while returning + a series of `NaN` values in Prometheus. Note that Grafana doesn't draw any lines or dots for `NaN` values, so usually the end result looks the same for both + VictoriaMetrics and Prometheus. Other PromQL functionality should work the same in MetricsQL. [File an issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues) if you notice discrepancies between PromQL and MetricsQL results other than mentioned above.