3.0 KiB
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| window() function | The window() function groups records based on a time value. |
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The window() function groups records based on a time value.
New columns are added to uniquely identify each window.
Those columns are added to the group key of the output tables.
A single input record will be placed into zero or more output tables, depending on the specific windowing function.
By default the start boundary of a window will align with the Unix epoch (zero time)
modified by the offset of the location option.
Function type: Transformation
Output data type: Object
window(
every: 5m,
period: 5m,
offset: 12h,
timeColumn: "_time",
startColumn: "_start",
stopColumn: "_stop",
createEmpty: false
)
// OR
window(
intervals: intervals(every: 5m, period: 5m, offset: 12h),
timeColumn: "_time",
startColumn: "_start",
stopColumn: "_stop",
createEmpty: false
)
Parameters
{{% note %}}
every,period or intervals is required.
{{% /note %}}
every
Duration of time between windows.
Defaults to period value.
Data type: Duration
period
Duration of the window.
Period is the length of each interval.
It can be negative, indicating the start and stop boundaries are reversed.
Defaults to every value.
Data type: Duration
offset
Offset is the duration by which to shift the window boundaries.
It can be negative, indicating that the offset goes backwards in time.
Defaults to 0, which will align window end boundaries with the every duration.
Data type: Duration
intervals
A function that returns an interval generator, a set of intervals used as windows.
Data type: Function
Example interval generator function
intervals(every:1d, period:8h, offset:9h)
{{% note %}}
When intervals is used, every, period, and start cannot be used or need to be set to 0.
{{% /note %}}
timeColumn
The column containing time.
Defaults to "_time".
Data type: String
startColumn
The column containing the window start time.
Defaults to "_start".
Data type: String
stopColumn
The column containing the window stop time.
Defaults to "_stop".
Data type: String
createEmpty
Specifies whether empty tables should be created.
Defaults to false.
Data type: Boolean
Examples
Window data into 10 minute intervals
from(bucket:"telegraf/autogen")
|> range(start:-12h)
|> window(every:10m)
// ...
Window data using intervals function
The following windows data into 8 hour intervals starting at 9AM every day.
from(bucket:"telegraf/autogen")
|> range(start:-12h)
|> window(intervals: intervals(every:1d, period:8h, offset:9h))