Handling global data

In the previous sections, we learned about pg_dump and pg_restore, which are two vital programs when it comes to creating backups. The thing is, pg_dump creates database dumps—it works at the database level. If we want to back up an entire instance, we have to use pg_dumpall or dump all of the databases separately. Before we dig into that, it makes sense to see how pg_dumpall works:

pg_dumpall > /tmp/all.sql

pg_dumpall will connect to one database after the other and send stuff to stdout, where you can process it with Unix. Note that pg_dumpall can be used just like pg_dump. However, it has some downsides. It does not support a custom or directory format, and therefore does not offer multi-core support. This means that we will be stuck with one thread.

However, there is more to pg_dumpall. Keep in mind that users live at the instance level. If you create a normal database dump, you will get all of the permissions, but you won’t get all...