![[assets/ex_gathermerge.png|256]] - **Description**: Collects results from parallel workers. - **Performance**: Collects results from parallel workers. - **Factors**: Number of workers, communication overhead. - **Cost**: `parallel worker cost + inter-process communication cost` - ![[assets/ex_gather_merge.svg|200x200]] - **Operates on**: [[Structures/Result Set]] - **Workloads**: - [[Workloads/IPC]] - [[Workloads/Sub/ExecuteGather]] - [[Workloads/Sub/ParallelFinish]] - [[Workloads/LWLock]] - [[Workloads/Sub/ParallelQueryDSA]] - [[Workloads/Sub/SharedTupleStore]]