libocci - when is it linked into Oracle.so?

Hi,

I have two DBD/Oracle/Oracle.so shared libraries. In one case ldd
reports that libocci is linked in, and in another case libocci doesn't
show up.

I don't know how the first version was built, but the second one was
build using:

export ORACLE_HOME=... # path the instantclient 10.2.0.4
export LB_LIBRARY_PATH="$ORACLE_HOME:"

perl Makefile.PL
make
make install

(I.e., a pretty generic build)

Does anyone know how libocci gets picked up when building Oracle.so? I
am using instantclient version 10.2.0.4

Thanks,
ER