On Fri, 10 Jan 2020 at 15:51, Sergei Kornilov <s...@zsrv.org> wrote: > > Hi > Thank you for update! I looked again > > (vacuum_indexes_leader) > + /* Skip the indexes that can be processed by parallel workers > */ > + if (!skip_index) > + continue; > > Does the variable name skip_index not confuse here? Maybe rename to something > like can_parallel? >
Again I looked into code and thought that somehow if we can add a boolean flag(can_parallel) in IndexBulkDeleteResult structure to identify that this index is supporting parallel vacuum or not, then it will be easy to skip those indexes and multiple time we will not call skip_parallel_vacuum_index (from vacuum_indexes_leader and parallel_vacuum_index) We can have a linked list of non-parallel supported indexes, then directly we can pass to vacuum_indexes_leader. Ex: let suppose we have 5 indexes into a table. If before launching parallel workers, if we can add boolean flag(can_parallel) IndexBulkDeleteResult structure to identify that this index is supporting parallel vacuum or not. Let index 1, 4 are not supporting parallel vacuum so we already have info in a linked list that 1->4 are not supporting parallel vacuum, so parallel_vacuum_index will process these indexes and rest will be processed by parallel workers. If parallel worker found that can_parallel is false, then it will skip that index. As per my understanding, if we implement this, then we can avoid multiple function calling of skip_parallel_vacuum_index and if there is no index which can't performe parallel vacuum, then we will not call vacuum_indexes_leader as head of list pointing to null. (we can save unnecessary calling of vacuum_indexes_leader) Thoughts? -- Thanks and Regards Mahendra Singh Thalor EnterpriseDB: http://www.enterprisedb.com
