Window transform
for dividing the elements in a PCollection into windows.See: Description
| Class | Description |
|---|---|
| BoundedWindow |
A
BoundedWindow represents a finite grouping of elements, with an
upper bound (larger timestamps represent more recent data) on the timestamps
of elements that can be placed in the window. |
| CalendarWindows |
A collection of
WindowingFns that windows values into calendar-based
windows such as spans of days, months, or years. |
| CalendarWindows.DaysWindows |
A
WindowingFn that windows elements into periods measured by days. |
| CalendarWindows.MonthsWindows |
A
WindowingFn that windows elements into periods measured by months. |
| CalendarWindows.YearsWindows |
A
WindowingFn that windows elements into periods measured by years. |
| FixedWindows |
A
WindowingFn that windows values into fixed-size timestamp-based windows. |
| GlobalWindow |
Default
WindowingFn where all data is in the same bucket. |
| GlobalWindow.Window |
The default window into which all data is placed.
|
| GlobalWindow.Window.Coder |
Coder for encoding and decoding Windows. |
| IntervalWindow |
An implementation of
BoundedWindow that represents an interval from
IntervalWindow.start (inclusive) to IntervalWindow.end (exclusive). |
| InvalidWindowingFn<W extends BoundedWindow> |
A
WindowingFn that represents an invalid pipeline state. |
| MergeOverlappingIntervalWindows |
A
WindowingFn that merges overlapping IntervalWindows. |
| NonMergingWindowingFn<T,W extends BoundedWindow> |
Abstract base class for
WindowingFns that do not merge windows. |
| PartitioningWindowingFn<T,W extends BoundedWindow> |
A
WindowingFn that places each value into exactly one window
based on its timestamp and never merges windows. |
| Sessions |
A WindowingFn windowing values into sessions separated by
Sessions.gapDuration-long
periods with no elements. |
| SlidingWindows |
A WindowingFn that windows values into possibly overlapping fixed-size
timestamp-based windows.
|
| Window |
Window logically divides up or groups the elements of a
PCollection into finite windows according to a WindowingFn. |
| Window.Bound<T> |
A
PTransform that windows the elements of a PCollection<T>,
into finite windows according to a user-specified WindowingFn<T, B>. |
| Window.Remerge<T> |
PTransform that does not change assigned windows, but will cause
windows to be merged again as part of the next
GroupByKey. |
| Window.Unbound |
An incomplete
Window transform, with unbound input/output type. |
| WindowingFn<T,W extends BoundedWindow> |
The argument to the
Window transform used to assign elements into
windows and to determine how windows are merged. |
Window transform
for dividing the elements in a PCollection into windows.
Window logically divides up or groups the elements of a
PCollection into finite windows according to a
WindowingFn.
The output of Window contains the same elements as input, but they
have been logically assigned to windows. The next
GroupByKeys, including one
within composite transforms, will group by the combination of keys and
windows.
Windowing a PCollection allows chunks of it to be processed
individually, before the entire PCollection is available. This is
especially important for PCollections with unbounded size, since the full
PCollection is never available at once.
For PCollections with a bounded size, by default, all data is implicitly in a
single window, and this replicates conventional batch mode. However, windowing can still be a
convenient way to express time-sliced algorithms over bounded PCollections.