If query takes only 4 seconds on Oracle side I would say connectivity is the issue.

Here is how you can trace Oracle side of the query...

Set your environment... e.g. ORACLE_HOME and ORACLE_SID

Initiate a SQLPlus session...

alter session set timed_statistics = true;

alter session set sql_trace = true;

set autotrace on explain

alter session set events='10046 trace name context forever, level 12';

++ EXECUTE TROUBLED SQL ++

alter session set sql_trace = false;

alter session set timed_statistics = false;

show parameter user_dump_destination

Go to whatever place user_dump_destination is pointing

tkprof the last large *.trc file you see there

Look at *.trf file looking for Wait Events section