One more query output I would like to give:-

SQL> select nvl(FILE#,0),nvl(BLOCK#,0),TYPE#,TS#,MAXEXTS,EXTENTS
2 from sys.seg$
3 where file#='76' or block#='120872'
4 and nvl(MAXEXTS-EXTENTS,0)<=4 and nvl(MAXEXTS-EXTENTS,0)>=0;

NVL(FILE#,0) NVL(BLOCK#,0) TYPE# TS# MAXEXTS EXTENTS
------------ ------------- ---------- ---------- ---------- ----------
193 120872 5 9 5 1


So for "OR" condition the query gives the result whereas for "AND" its failing.

Thanks,
Pallavi.