| Transform | Description |
|---|
| Filter | Given a predicate, filter out all elements that don't satisfy the predicate. |
| FlatMap | Applies a function that returns a collection to every element in the input and
outputs all resulting elements. |
| Keys | Extracts the key from each element in a collection of key-value pairs. |
| KvSwap | Swaps the key and value of each element in a collection of key-value pairs. |
| Map | Applies a function to every element in the input and outputs the result. |
| ParDo | The most-general mechanism for applying a user-defined DoFn to every element
in the input collection. |
| Partition | Routes each input element to a specific output collection based on some partition
function. |
| Regex | Filters input string elements based on a regex. May also transform them based on the matching groups. |
| Reify | Transforms for converting between explicit and implicit form of various Beam values. |
| ToString | Transforms every element in an input collection a string. |
| WithTimestamps | Applies a function to determine a timestamp to each element in the output collection,
and updates the implicit timestamp associated with each input. Note that it is only
safe to adjust timestamps forwards. |
| Values | Extracts the value from each element in a collection of key-value pairs. |
| Transform | Description |
|---|
| ApproximateQuantiles | Not available. See BEAM-6694 for updates. |
| ApproximateUnique | Not available. See BEAM-6693 for updates. |
| CoGroupByKey | Takes several keyed collections of elements and produces a collection where each element consists of a key and all values associated with that key. |
| CombineGlobally | Transforms to combine elements. |
| CombinePerKey | Transforms to combine elements for each key. |
| CombineValues | Transforms to combine keyed iterables. |
| CombineWithContext | Not available. |
| Count | Counts the number of elements within each aggregation. |
| Distinct | Produces a collection containing distinct elements from the input collection. |
| GroupByKey | Takes a keyed collection of elements and produces a collection where each element consists of a key and all values associated with that key. |
| GroupIntoBatches | Batches the input into desired batch size. |
| Latest | Gets the element with the latest timestamp. |
| Max | Gets the element with the maximum value within each aggregation. |
| Mean | Computes the average within each aggregation. |
| Min | Gets the element with the minimum value within each aggregation. |
| Sample | Randomly select some number of elements from each aggregation. |
| Sum | Sums all the elements within each aggregation. |
| Top | Compute the largest element(s) in each aggregation. |