ok, what i am sharing, *DO NOT DO IT.* it is just to answer why it is not working :) PostgreSQL: Documentation: 13: 19.17. Developer Options <https://www.postgresql.org/docs/current/runtime-config-developer.html>
postgres=# alter table pg_catalog.pg_largeobject_metadata set (AUTOVACUUM_VACUUM_COST_DELAY = 1); ERROR: permission denied: "pg_largeobject_metadata" is a system catalog postgres=# show allow_system_table_mods; allow_system_table_mods ------------------------- off (1 row) postgres=# set allow_system_table_mods TO 1; SET postgres=# show allow_system_table_mods; allow_system_table_mods ------------------------- on (1 row) postgres=# alter table pg_catalog.pg_largeobject_metadata set (AUTOVACUUM_VACUUM_COST_DELAY = 1); ALTER TABLE but you can always run vacuum manually on the table. vacuum (verbose,analyze) pg_catalog.pg_largeobject_metadata; INFO: vacuuming "pg_catalog.pg_largeobject_metadata" INFO: index "pg_largeobject_metadata_oid_index" now contains 0 row versions in 1 pages DETAIL: 0 index row versions were removed. 0 index pages have been deleted, 0 are currently reusable. CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s. INFO: "pg_largeobject_metadata": found 0 removable, 0 nonremovable row versions in 0 out of 0 pages DETAIL: 0 dead row versions cannot be removed yet, oldest xmin: 8083775 There were 0 unused item identifiers. Skipped 0 pages due to buffer pins, 0 frozen pages. 0 pages are entirely empty. CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s. INFO: analyzing "pg_catalog.pg_largeobject_metadata" INFO: "pg_largeobject_metadata": scanned 0 of 0 pages, containing 0 live rows and 0 dead rows; 0 rows in sample, 0 estimated total rows VACUUM On Fri, 4 Jun 2021 at 20:10, Zwettler Markus (OIZ) < markus.zwett...@zuerich.ch> wrote: > I would like to start a more aggressive autovacuum on pg_catalog tables > like pg_largeobject. > > > > So I tried as a superuser: > > > > # alter table pg_catalog.pg_largeobject_metadata set > (autovacuum_vacuum_scale_factor = 0, autovacuum_vacuum_threshold = 5000); > > ERROR: permission denied: "pg_largeobject_metadata" is a system catalog > > > > (How) Is it possible to change such table attributes on pg_catalog tables? > > > > Thanks, Markus > > > > > -- Thanks, Vijay Mumbai, India
