The original Oracle version on this NT box is 8.0.5. Last year, a DBA installed 8.1.6 and upgraded all databases. And then applied 8.1.6.3 patch to fix some other problems. Ever since the patch installed, this end of communcation channel error started to occur.

SQL> select distinct owner from dba_segments;

OWNER
------------------------------
BSTAR
OUTLN
SCOTT
SPLASH21
SYS
SYSTEM
WEBORDER

7 rows selected. --------------------- OK.

SQL> select extents from dba_segments;
select extents from dba_segments
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel ----------------- NOT OK.
--------------------------------------------------------------------------------------------
It seems when I select the static columns of dba_segments, like owner, max_extents, the query goes through. But when I select the dynamic columns, like extents, bytes, get ORA-03113 error. Anything you can think about related to this issue will be deserved a try.

Thank you