importing postgres tar file throws parallel not supported in postgres 12
Because the &quot;tar&quot; format cannot be restored in parallel.
Use the &quot;custom&quot; or &quot;directory&quot; format of pg_dump so that it can be restored with parallel processes.
But Jeff had a good idea (see the comment): If you untar the backup into a directory, you can then do a parallel restore by pointing pg_restore to that directory.