I think this depends on the compiler you're planning on using. The documentation you read probably refers to compiling the beast with the standard HPUX C-compiler and linker, which needs the +z flag to generate position independent code.

The flags including -fPIC are flags for GCC. If you have gcc on HPUX (it's available from HP's site), you will probably save yourself worlds of grief by using that instead of the HP compiler (setting the CC environment variable to the location of your gcc binary will do the trick).

I can't help you with your other questions though, as I've never installed DBD::Oracle anywhere and the variables to set seem positively alien to me (cccdlflags ???). Sorry :).

CU
Robartes-