Mar 13, 2026: New OVERLAP_POLICY parameter for task graphs¶

The new OVERLAP_POLICY parameter for task graphs replaces the deprecated ALLOW_OVERLAPPING_EXECUTION parameter and provides more granular control over concurrent task graph execution. You can set this parameter on a root task using CREATE TASK or ALTER TASK.

OVERLAP_POLICY supports three values:

• NO_OVERLAP (default): Executes tasks serially. The next run of a root task is scheduled only after all child tasks finish running.

• ALLOW_CHILD_OVERLAP: Allows child task parallelism. A new instance of the task graph can start while child tasks from a previous run are still executing. Root tasks never overlap with this policy.

• ALLOW_ALL_OVERLAP: Allows true parallelism. Multiple instances of the entire task graph, including the root task, can run concurrently.

For backward compatibility, ALLOW_OVERLAPPING_EXECUTION = TRUE maps to OVERLAP_POLICY = ALLOW_CHILD_OVERLAP, and ALLOW_OVERLAPPING_EXECUTION = FALSE maps to OVERLAP_POLICY = NO_OVERLAP.

For more information, see Create a sequence of tasks with a task graph.