On Mon, Mar 4, 2019 at 5:38 AM Tatsuro Yamada <yamada.tats...@lab.ntt.co.jp> wrote: > === Current design === > > CLUSTER command uses Index Scan or Seq Scan when scanning the heap. > Depending on which one is chosen, the command will proceed in the > following sequence of phases: > > * Scan method: Seq Scan > 0. initializing (*2) > 1. seq scanning heap (*1) > 3. sorting tuples (*2) > 4. writing new heap (*1) > 5. swapping relation files (*2) > 6. rebuilding index (*2) > 7. performing final cleanup (*2) > > * Scan method: Index Scan > 0. initializing (*2) > 2. index scanning heap (*1) > 5. swapping relation files (*2) > 6. rebuilding index (*2) > 7. performing final cleanup (*2) > > VACUUM FULL command will proceed in the following sequence of phases: > > 1. seq scanning heap (*1) > 5. swapping relation files (*2) > 6. rebuilding index (*2) > 7. performing final cleanup (*2) > > (*1): increasing the value in heap_tuples_scanned column > (*2): only shows the phase in the phase column
All of that sounds good. > The view provides the information of CLUSTER command progress details as > follows > # \d pg_stat_progress_cluster > View "pg_catalog.pg_stat_progress_cluster" > Column | Type | Collation | Nullable | Default > ---------------------------+---------+-----------+----------+--------- > pid | integer | | | > datid | oid | | | > datname | name | | | > relid | oid | | | > command | text | | | > phase | text | | | > cluster_index_relid | bigint | | | > heap_tuples_scanned | bigint | | | > heap_tuples_vacuumed | bigint | | | Still not sure if we need heap_tuples_vacuumed. We could try to report heap_blks_scanned and heap_blks_total like we do for VACUUM, if we're using a Seq Scan. > === Discussion points === > > - Progress counter for "3. sorting tuples" phase > - Should we add pgstat_progress_update_param() in tuplesort.c like a > "trace_sort"? > Thanks to Peter Geoghegan for the useful advice! How would we avoid an abstraction violation? > - Progress counter for "6. rebuilding index" phase > - Should we add "index_vacuum_count" in the view like a vacuum progress > monitor? > If yes, I'll add pgstat_progress_update_param() to reindex_relation() > of index.c. > However, I'm not sure whether it is okay or not. Doesn't seem unreasonable to me. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
