Handling various formats

So far, we have seen that pg_dump can be used to create text files. The problem here is that a text file can only be replayed completely, so if we have saved an entire database, we can only replay the entire thing. In most cases, this is not what we want to do. Therefore, PostgreSQL has additional formats that offer more functionality.

At this point, four formats are supported:

-F, --format=c|d|t|p  output file  format (custom, directory, tar, plain  text  (default))

We have already seen plaintext, which is just normal text. On top of that, we can use a custom format. The idea behind a custom format is to get a compressed dump, including a table of contents. Here are two ways to create a custom format dump:

[hs@linuxpc ~]$ pg_dump -Fc test > /tmp/dump.fc
[hs@linuxpc ~]$ pg_dump -Fc test -f /tmp/dump.fc

In addition to the table of contents, the compressed dump has one more advantage: it is a lot smaller...