Starts one or more transforms.
If the Elasticsearch security features are enabled, you must have the following built-in roles and privileges:
When you start a transform, it creates the destination index if it
does not already exist. The
number_of_shards is set to
1 and the
auto_expand_replicas is set to
The transform deduces the mapping definitions from the source indices. For
scripted fields, it uses dynamic mappings. If a field in the
destination index is created by
aggregations, the transform uses dynamic mappings unless a template exists or
the destination index already exists. Mapping definitions in the destination
index take precedence over dynamic mappings and templates.
When the transform starts, a series of validations occur to ensure its success. If you deferred validation when you created the transform, they occur when you start the transform—with the exception of privilege checks. When Elasticsearch security features are enabled, the transform remembers which roles the user that created it had at the time of creation and uses those same roles. If those roles do not have the required privileges on the source and destination indices, the transform fails when it attempts unauthorized operations.
- (Required, string) Identifier for the transform. This identifier can contain lowercase alphanumeric characters (a-z and 0-9), hyphens, and underscores. It must start and end with alphanumeric characters.