[collectd] Problem in compiling ORACLE plugin

[ROMAGNOLI Carlo]

Ciao,
after a succcesfully installation of "oracle instant client 11.2" i cannot compile the oracle plug in.
The error was (Symbol 'OCIEnvCreate' not found) and in the config.log i see 
configure:20337: checking for OCIEnvCreate
configure:20337: gcc -o conftest -g -O2  -I/home/xxx/instantclient/rdbms/public  -L/home/xxx/instantclient/lib -lclntsh conftest.c -ldl  >&5
/usr/bin/ld: skipping incompatible /home/xxx/instantclient/lib/libclntsh.so when searching for -lclntsh
/usr/bin/ld: cannot find -lclntsh

i try many version of the library...with the same result.
Some one can help me?
Tks
Carlo