Matching a column from a table to another table
Try this one:

SELECT  PRIV.id_extern_for_job
,       PRIV.id
,       PUB.id_extern_for_job
FROM    SOL_PUBLIC.SOL_SUBSOL_CHESTIONARE@RACDB     PUB
,       SOL.SOL_SUBSOL_CHESTIONARE                  PRIV
WHERE   PRIV.id_extern_for_job = PUB.id
AND     PRIV.id &lt;&gt; PUB.id_extern_for_job;