Looks like a postgres backup/dump structure (A sort of a forensic/data archeology question) I was given a compressed folder that contains number of subdirectories, and, among others, directories named .pgdir with number of numerically sequenced files in a &lt;9999>.dat.gz format and one in a toc.dat format.

I cannot post the content of the files, but when I uncompress the &lt;9999>.dat.gz, they each contain pretty structured, tab-separated tabular data with \N [sic] at the end line.
toc.dat has a mix of binary and strings, starting with PGDMP where I can recognize some postgres DDL statements, schema creation. etc. 

To me, this looks like a postgres backup, but I am not familiar with this layout and how to restore it.

Is anyone familiar with these structures, and how could they be used to restore the database?
Use pg_restore to list its contents, dump it to SQL, or restore it to a database.