importing postgres tar file throws parallel not supported in postgres 12 I'm trying to import a db that someone sent me: testdb.tar (43GB size)
First I've imported using:
pg_restore --host localhost --port 5432 --username postgres --dbname testdb --role postgres --no-password  --verbose testdb.tar

It took 23 hours to complete.
I supose it used just a single core.
Now, trying to do it faster, using the available 16 cores, I tried:
pg_restore --host localhost --port 5432 --username postgres --dbname testdb --role postgres --no-password -j 16 --verbose testdb.tar

However, it throws the following error:
pg_restore: error: parallel restore is not supported with this archive file format

Not really sure why it complains.
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.