Build Notes
The 32 bit version of the MySQL database must be installed on the system
on which you will build.   The DBD-mysql will run with either the 64 bit or
32 bit version,  but must be built with the 32 bit version.

For example:  Download mysql-5.1.37-aix5.3-powerpc.tar.gz ( 32bit version) or
the latest release (See http://dev.mysql.com/downloads/mysql/5.1.html#aix)
 and untar on the build machine in the /usr/local directory.   
cd /usr/local/mysql   
ln -s mysql-5.1.37-aix5.3-powerpc mysql 

Need cc_r compiler installed on AIX build system. 

Download DBD-mysql-4.007.tar.gz from CPAN.

cp DBD-mysql-4.007.tar.gz /opt/freeware/src/packages/BUILD directory 

Use the DBD-mysql.spec provided in this directory and
cp DBD-mysql.spec /opt/freeware/src/packages/SPECS 

cd /opt/freeware/src/packages/SPECS
rpm -bb DBD-mysql.spec

Creates:
/opt/freeware/src/packages/RPMS/ppc/perl-DBD-mysql-4.007-1.aix5.3.ppc.rpm