On Sun, Dec 1, 2019 at 11:01 PM Sergei Kornilov <s...@zsrv.org> wrote:
> Hi > > > I think I got your point. Your proposal is that it's more efficient if > > we make the leader process vacuum the index that can be processed only > > the leader process (i.e. indexes not supporting parallel index vacuum) > > while workers are processing indexes supporting parallel index vacuum, > > right? That way, we can process indexes in parallel as much as > > possible. > > Right > > > So maybe we can call vacuum_or_cleanup_skipped_indexes first > > and then call vacuum_or_cleanup_indexes_worker. But I'm not sure that > > there are parallel-safe remaining indexes after the leader finished > > vacuum_or_cleanup_indexes_worker, as described on your proposal. > > I meant that after processing missing indexes (not supporting parallel > index vacuum), the leader can start processing indexes that support the > parallel index vacuum, along with parallel workers. Your idea is good, but remember we have always considered a leader as one worker if the leader can participate. If we do what you are suggesting that won't be completely true as a leader will not completely participate in a parallel vacuum. It might be that we don't consider leader equivalent to one worker in the presence of indexes that don't support a parallel vacuum, but I am not sure if that really matters much. I think overall it should not matter much because we won't have that many indexes that don't support a parallel vacuum. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
