On Mon, 2021-08-30 at 13:38 -0400, Mladen Gogala wrote: > According to unsubstantiated rumors from https://www.postgresql.org/docs/13/catalog-pg-class.html, > the definition of RELFILENODE column is as follows: > > relfilenode oid > > Name of the on-disk file of this relation; zero means this is a “mapped” relation whose disk > file name is determined by low-level state > Change of the RELFILENODE means that the relation has got a new file. And that means that vacuum full > rewrites the table, just as Laurenz has said. Note that OID itself is NOT changed. Please don't top-post on these lists. I am not sure what you mean with "unsubstantiated". Note that this will be 0 for certain crucial system tables (essentially those that have to be accessed *before* regular metadata queries can be executed). So it is better to use the "pg_relation_filenode()" function to find the file that belongs to a certain table. You can use that to find which files do *not* belong to any table, index, sequence or materialized view and then delete those. But I would think twice before manually deleting files in the data directory. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
