add_merge_on_top

datafusion_physical_optimizer::enforce_distribution

Function add_merge_on_top 

Source 
fn add_merge_on_top(input: DistributionContext) -> DistributionContext
Expand description

Adds a SortPreservingMergeExec or a CoalescePartitionsExec operator on top of the given plan node to satisfy a single partition requirement while preserving ordering constraints.

§Parameters

  • input: Current node.

§Returns

Updated node with an execution plan, where the desired single distribution requirement is satisfied.