highestCurrent() function
The highestCurrent() function selects the last record of each table in the input stream and returns the top n records.
It outputs a single aggregated table containing n records.
Function type: Selector, Aggregate
highestCurrent(
n:10,
column: "_value",
groupColumns: []
)
Empty tables
highestCurrent() drops empty tables.
Parameters
n
Number of records to return.
Data type: Integer
column
Column by which to sort.
Default is "_value".
Data type: String
groupColumns
The columns on which to group before performing the aggregation.
Default is [].
Data type: Array of strings
Examples
from(bucket:"example-bucket")
|> range(start:-1h)
|> filter(fn: (r) =>
r._measurement == "mem" and
r._field == "used_percent"
)
|> highestCurrent(n:10, groupColumns: ["host"])
Function definition
// _sortLimit is a helper function, which sorts and limits a table.
_sortLimit = (n, desc, columns=["_value"], tables=<-) =>
tables
|> sort(columns:columns, desc:desc)
|> limit(n:n)
// _highestOrLowest is a helper function which reduces all groups into a single
// group by specific tags and a reducer function. It then selects the highest or
// lowest records based on the column and the _sortLimit function.
// The default reducer assumes no reducing needs to be performed.
_highestOrLowest = (n, _sortLimit, reducer, column="_value", groupColumns=[], tables=<-) =>
tables
|> group(columns:groupColumns)
|> reducer()
|> group(columns:[])
|> _sortLimit(n:n, columns:[column])
highestCurrent = (n, column="_value", groupColumns=[], tables=<-) =>
tables
|> _highestOrLowest(
n:n,
column:column,
groupColumns:groupColumns,
reducer: (tables=<-) => tables |> last(column:column),
_sortLimit: top,
)
Support and feedback
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- Post in the InfluxData Community.
- Submit documentation issues to the InfluxDB 2.0 documentation repository.
- Submit InfluxDB issues to the InfluxDB repository.
For our InfluxDB Cloud customers, InfluxData Support is also available.