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Version: 2.0.0

Table Commit Triggers

A Table trigger runs a Function whenever one of the Tables it watches receives a new Version. This is what makes a pipeline cascade: a Publisher commits, the Transformers reading that Table run, they commit in turn, and the chain continues to the Subscribers at the end.

Configure it with the trigger_by list on the decorator.

The three configurations​

Omitted. Transformers and Subscribers fire on a commit to any of their input Tables. Publishers have no input Tables, so they get no automatic trigger at all and run manually or on a schedule.

An empty list. trigger_by=[] disables automatic triggering. Use it when a Transformer or Subscriber should read its input Tables but not wake up when they change.

A non-empty list. The Function watches exactly the Tables named and nothing else. This is how you trigger on a subset of the input Tables, or on a Table the Function does not read at all.

@transformer(
    trigger_by=["sales", "inventory/stock"],
    input_tables=["sales"],
    output_tables=["sales_by_rep"],
)
def summarize(sales: TableFrameSpec) -> TableFrameSpec:
    return sales

Referencing another Collection's Tables​

Write a Table outside the Function's own Collection as collection/table, as inventory/stock does above. Unqualified names resolve inside the Function's own Collection.

Cross-Collection references work only within a single Project. A reference that crosses Projects surfaces as Dependency table '<x>' does not exist, because the row is not visible rather than missing.

A Table cannot trigger the Function that writes it.

A commit is not the same as a change​

Every run that returns data commits a new Version, whether or not the rows differ from the previous one. A Publisher writing three Tables commits all three on every run, so a Function watching any of them fires each time, even for the Tables whose contents were identical.

Returning None from a slot is the exception: it commits nothing and leaves the current Version in place, so downstream Functions watching that Table do not fire.