You should use one of the tools listed in Table 18–1 to remove a package, even though you might be tempted to use the rm command instead. For example, you could use the rm command to remove a binary executable file. However, doing so is not the same as using the pkgrm command to remove the software package that includes that binary executable. Using the rm command to remove a package's files will corrupt the software products database. If you really only want to remove one file, you can use the removef command. This command will update the software product database correctly so that the file is no longer a part of the package. For more information, see the removef(1M) man page.
If you intend to keep multiple versions of a package, install new versions into a different directory than the already installed package by using the pkgadd command. For example, if you intended to keep multiple versions of a document processing application. The directory where a package is installed is referred to as the base directory. You can manipulate the base directory by setting the basedir keyword in a special file called an administration file. For more information on using an administration file and on setting the base directory, see Avoiding User Interaction When Adding Packages (pkgadd) and the admin(4) man page.
If you use the upgrade option when installing Solaris software, the Solaris installation software checks the software product database to determine the products that are already installed on the system.