Hotfix Readme


What is a Hotfix?

A Hotfix is simply a self-extracting zip file that contains the modified files necessary to fix a customer's problem.
When a Hotfix is executed, it extracts itself and then automatically starts installation by running 'hotfix.exe'


Why do we have Hotfixes?

Hotfixes are required due to the way Fixpak images work.  Fixpak images contain the binary differences of modified
files.  The binary difference of a file is the byte difference between the new (modified) file and the file that was
previously released.  When applying a new Fixpak on GA, FP1, FP2, FP3, or any other previously released level,
consistency is required in all of the file levels in the current SQLLIB folder.  This is required because the binary
differences that are stored in a Fixpak are based on the previously released levels.  This introduces a problem when
updating only specific files, which is done when a customer finds a problem that needs to be immediately fixed.
Customers cannot just be given the files that were modified to fix their problem, because this would make the levels
of the updated files inconsistent with the rest of the files in the SQLLIB folder.  This inconsistency will not allow
the customer to apply any future Fixpaks.  If the customer tries to install a new Fixpak, the Fixpak will discover the
inconsistencies in the file's levels, and abort its installation.  To fix this problem, Hotfixes are used for Windows
customers.


How does a Hotfix work?

After extracting itself, the Hotfix does two things.  First it backs up the files from the SQLLIB folder that it will
be replacing.  It accomplishes this by renaming the files to <filename>.hfb#  For example, every Hotfix replaces the
file 'db2install.dll', so the Hotfix will rename this file to db2install.dll.hfb0 When this is complete, the Hotfix
will copy the new files into their corrsponding locations in the SQLLIB folder.  Properly backing up the modified
files is the major purpose of a Hotfix.  Now that the modified files have been backed up, future Fixpak releases can
be properly installed.  When installing a new Fixpak, the Fixpak installation will be able to recognize any special
builds installed on the system by the backed up files.  The Fixpak will then uninstall all Hotfixes that are currently
on the system before installing the new Fixpak.  The Fixpak will accomplish this by restoring all of the backed up
files in the SQLLIB folder, which will bring all of the modified files back to their original release level.  Once
this is completed, the Fixpak will then install itself.


How do I install a Hotfix?

To install a Hotfix, make sure all DB2 processes are stopped.  You can use the Task Manager to kill all of the running
DB2 processes, or click on the Service icon in the Control Panel, and use it to stop all of the running processes.
After all DB2 processes are stopped, simply double-click on the Hotfix file, or run it from the command line.  Please
note that Hotfixes are not Fixpak images.  This means that unlike a Fixpak, a Hotfix can only be installed on top of a
specific release.  For example, if the Hotfix is built on top of Fixpak 3 (as this one is), you can ONLY install the
Hotfix on top of Fixpak 3.  If the customer attempts to install a Hotfix on an improper release, the SQLLIB will become
corrupted.


What are the command options for a Hotfix?

Please run the hotfix from any folder outside of the SQLLIB folder.
Errors may occur if a hotfix is installed from this folder.

The following are the command line options to use with a Hotfix:

"Hotfix -l"             - Displays a list of hotfixes (HotFixIDs) that are currently installed on
                                   the system
"Hotfix -f"             - Kills all DB2 processes
"Hotfix -u HotFixID"    - Uninstalls the specified Hotfix
                          The HotfixID parameter is the value shown when running "Hotfix -l"
"Hotfix -u all"         - Uninstalls all hotfixes
"Hotfix -h"             - Displays help


PSoft_10537_v81_fp5a_windows_64.exe is a HotFix that can be applied to 64-bit Windows operating systems where DB2 version
8.1 FixPak 5 is already installed.

PSoft_10536_v81_fp5a_windows_32.exe is a HotFix that can be applied to 32-bit Windows operating systems where DB2 version
8.1 FixPak 5 is already installed.