i managed to solve my problem. the missing component was 'Oracle Call Interfaces'. strangely, on Solaris 8 this component was not available in the Oracle9i (64-bit) installer if i chose the client installation (though it is available on Linux and 64-bit HP-UX)!
i had to first choose Oracle9i Client installation with Custom installation type and the following components:
Oracle Network Utilities
Oracle Database Utilities
SQL*Plus
Oracle Programmer
Oracle Universal Installer
then i reran the installer and chose Oracle9i Database with Custom installation and the following component:
Oracle9i Database / Oracle9i Development Kit / Oracle Call Interface (OCI)
finally i installed the Oracle9iR2 patch set 2 9.2.0.3.0 (64-bit) for Solaris.
now DBD::Oracle v1.15 compiles on my system.
best regards,
--
aspa