Currently I have something like that:
NVL(COL1, NVL(COL2, NVL(COL3, NVL(COL4, NVL(COL5, COL6)))))
Is in Oracle 11gR2 any function that returns first NOT NULL parameter ?
Perhaps you are looking for COALESCE()?
Note that COALESCE() is supported on almost all khown databases: Oracle, PostgreSQL, MySQL, MSSQL, SQLite.