prometheus/docs/disabled_features.md

---
title: Disabled Features
sort_rank: 10
---

# Disabled Features

Here is a list of features that are disabled by default since they are breaking changes or are considered experimental.
Their behaviour can change in future releases which will be communicated via the [release changelog](https://github.com/prometheus/prometheus/blob/master/CHANGELOG.md).

You can enable them using the `--enable-feature` flag with a comma separated list of features.
They may be enabled by default in future versions.

## `@` Modifier in PromQL

`--enable-feature=promql-at-modifier`

This feature lets you specify the evaluation time for instant vector selectors,
range vector selectors, and subqueries. More details can be found [here](querying/basics.md#@-modifier).
'@ <timestamp>' modifier (#8121) This commit adds `@ <timestamp>` modifier as per this design doc: https://docs.google.com/document/d/1uSbD3T2beM-iX4-Hp7V074bzBRiRNlqUdcWP6JTDQSs/edit. An example query: ``` rate(process_cpu_seconds_total[1m]) and topk(7, rate(process_cpu_seconds_total[1h] @ 1234)) ``` which ranks based on last 1h rate and w.r.t. unix timestamp 1234 but actually plots the 1m rate. Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in> 2021-01-20 02:57:39 -08:00			`---`
			`title: Disabled Features`
			`sort_rank: 10`
			`---`

			`# Disabled Features`

			`Here is a list of features that are disabled by default since they are breaking changes or are considered experimental.`
			`Their behaviour can change in future releases which will be communicated via the [release changelog](https://github.com/prometheus/prometheus/blob/master/CHANGELOG.md).`

			You can enable them using the `--enable-feature` flag with a comma separated list of features.
			`They may be enabled by default in future versions.`

			## `@` Modifier in PromQL

			`--enable-feature=promql-at-modifier`

			`This feature lets you specify the evaluation time for instant vector selectors,`
			`range vector selectors, and subqueries. More details can be found [here](querying/basics.md#@-modifier).`