Comparing values from different buckets

This page documents an earlier version of InfluxDB OSS. InfluxDB 3 Core is the latest stable version.

API token hashing is enabled by default in InfluxDB OSS 2.9.0

Stronger token security: tokens are stored as hashes on disk, so a copy of the database file doesn’t expose usable tokens. Existing tokens are hashed on first startup and the original strings can’t be recovered afterward — capture any plaintext tokens you still need before you upgrade.

For more information, see Token hashing.

This example uses NOAA water sample data.

This example compares the value from the latest point to an average value stored in another bucket. This is useful when using the average value to calculate a threshold check.

The following query:

  • Uses range() to define a time range.
  • Gets the last value in the means bucket and compares it to the last value in the noaa bucket using last().
  • Uses join() to combine the results
  • Uses map() to calculate the differences
means = from(bucket: "weekly_means")
    |> range(start: 2019-09-01T00:00:00Z)
    |> last()
    |> keep(columns: ["_value", "location"])

latest = from(bucket: "noaa")
    |> range(start: 2019-09-01T00:00:00Z)
    |> filter(fn: (r) => r._measurement == "average_temperature")
    |> last()
    |> keep(columns: ["_value", "location"])

join(tables: {mean: means, reading: latest}, on: ["location"])
    |> map(fn: (r) => ({r with deviation: r._value_reading - r._value_mean}))

Example results

location_value_mean_value_readingdeviation
coyote_creek79.82710622710623899.172893772893772
santa_monica80.20451339915374854.79548660084626
queries

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