Information regarding the split distribution
In the various download directories you will find alongside files with
(where XXX is a version number) smaller files with the names
The file named "postgresql-XXX.tar.gz" is the full source distribution.
Each of the other four "tarballs" contains a subset of the files from the
full distribution, for downloading convenience. If you download all four
of them and unpack them into the same directory you will get exactly what
you would have gotten had you downloaded the full distribution.
The -base package is the only one that is required for successful
installation. It contains the server and the essential client interfaces.
The -opt package contains all parts whose compilation needs to be enabled
explicitly. This includes the C++, JDBC, ODBC, Perl, Python, and Tcl
interfaces, as well as multibyte support. The -docs package contains the
documentation in HTML format (man pages are in -base) and the
documentation sources. You don't need to download this package if you
intend to browse the documentation on the web. Finally, the -test package
contains the regression test suite.
(Note, this scheme is new as of version 7.1RC4. Previous versions used a
different, incompatible split where all subpackages where required.)