Compute if expression absent

Supported in: Batch

Computes the expression for new rows, the value for a given key will only ever be computed once, even across builds.

Transform categories: Other

Declared arguments

• Dataset - Dataset to apply expression to.
  Table
• Expression - Expression to compute when no result exists for key.
  Expression<AnyType>
• Key - Results are stored under this key. For a given key, a result will never be computed twice.
  List<Expression<Binary | Boolean | Byte | Integer | Long | Short | String>>
• Store id - The id for the store to store results under. If this id is changed, all results will be invalidated. The same id cannot be used twice in the same pipeline.
  Literal<String>
• optional Disable store - If true, the store is fully disabled and all store parameters are ignored. At this point the transform will operate like a regular apply expression.
  Literal<Boolean>
• optional Do not store results when - Some results may not be desired to store. For example, an error result or null result. Given the result, choose what values should not be stored. When not present, all results (even nulls) will be stored.
  Expression<Boolean>