> I have a PG (v16) instance which is occupying around 1TB of storage. Out of > this, around 350GB is occupied by the table pg_catalog.pg_attribute. > Why is the catalog table's size so big?
Heavy use of temp tables is a known cause of this.
> I think this table must have tons of dead tuples. Please suggest to me if > we can purge any data/shrink the size of this table.
Yeah, I'd also bet that there are tons of dead tuples, or just unused free space. To purge it you would use VACUUM FULL, though that would need to lock all accesses to the table.
Does your instance run with autovacuum disabled perchance?
or long unclosed transactions, maybe forgotten replication slots, ...
It is very strange so with this size it is still usable. Today hardware is unbelievable strong
Regards
Pavel
-- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ Bob [Floyd] used to say that he was planning to get a Ph.D. by the "green stamp method," namely by saving envelopes addressed to him as 'Dr. Floyd'. After collecting 500 such letters, he mused, a university somewhere in Arizona would probably grant him a degree. (Don Knuth)
