I have a legacy system that uses `Posgresql 9.6` and `Ubuntu 16.04`. Everything was fine several days ago even with standard Postgresql settings. I dumped a database with the compression option (maximum compression level -Z 9) in order to have a smaller size (`pg_dump --compress=9 database_name > database_name.sql`). After that I got a lot of problems.
You describe taking a dump of the database, but don't describe doing anything with it. Did you replace your system with one restored from that dump? If so, did vacuum and analyze afterwards?
