Restore Postgresql database from table files

Question

Is it possible to restore a Postgres database when only having access to the table files under $PGDATA/base/<db_oid>? The system catalogs are empty.

Background

Somebody with sudo executed an rm -Rf under /var/lib. Random files where deleted, but not the ones of the database I am interested in. Postgres would not start, even after I restored several files/directories by hand. So I created a new $PGDATA and copied the database files in, hoping that Postgres would automatically read them. Apparently, Postgres relies a lot on its system catalogs to maintain links between what is on disk and what the user sees.

• Laurenz Albe: Without the commit log and the global tablespace, it will take an expert to extract anything.

Answer 1

This doesn't sound promising. Do you know how you got into this predicament?

What specific system tables are empty? A good chunk of the system catalogs are located inside $PGDATA/base/<db_oid>

Do you have any recent backups that could be used to splice together whatever it is that you are missing?

Of course the first step it to make a backup of the current state of things, so if you somehow make things even worse you can go back and try again.

• Georgios Gousios: Thanks! I 've updated the question with some background info.