some questions on building PostGIS from Source

Question

From the PostGIS manual about Compiling and Install from source I get the general procedure to be ...

1. Install postgres
2. get a couple of libraries PostGIS depends on
3. download and extract the PostGIS sources
4. run the configure shell script
5. run make

that should build PostGIS against (and only working with) the current installed postgres version.

now my questions

1. will you get something out of the build process that you can move to other machines with the same postgres version (and the required libraries) and use it there as well, or
2. build PostGIS into the running postgres installation and be able to use it on that exact machine in that exact combination?
3. if you want to upgrade PostGIS ... do you have to remove the old version after the migration? if so, how do you do that exactly?

Answer 1

As respects your questions:

1 & 2. The version and products for your build will be specific to the build host. If you want to install the same products on another identical server, the easiest way is to NFS mount the build directory and run make install on the target. Again, the target must be identical, including installation of dependent libraries. It's far easier to use your platform's packaging system instead, especially if you need to install PostGIS on a large number of servers. Package management is out of scope for dba.SE.

3. Upgrade instructions are in the manual.