pr: 129606
summary: Release FORK in tech preview
area: ES|QL
type: feature
issues: []
highlight:
  title: Release FORK in tech preview
  body: |-
    Fork is a foundational building block that allows multiple branches of execution.
    Conceptually, fork is:
    - a bifurcation of the stream, with all data going to each fork branch, followed by
    - a merge of the branches, enhanced with a discriminator column called FORK:

    Example:

    [source,yaml]
    ----------------------------
    FROM test
    | FORK
    ( WHERE content:"fox" )
    ( WHERE content:"dog" )
    | SORT _fork
    ----------------------------

    The FORK command add a discriminator column called `_fork`:

    [source,yaml]
    ----------------------------
    | id  | content   | _fork |
    |-----|-----------|-------|
    | 3   | brown fox | fork1 |
    | 4   | white dog | fork2 |
    ----------------------------

  notable: true
