I'm issuing a simple drop table cascade constraints table , but it is hanging forever. After waiting for hours, if I press the cancel button in the SQL Developer, it says "User cancelled operation" like I'm the culprit. Please advice, before I shoot myself.
After hanging for a long time it pops up a dialog box as follows:
Error encountered: An error was encountered performing the requested operation:
ORA-00600: internal error code, arguments: [15264],[],[],[],[],[],[],[]
*Cause: This is the generic internal error number for Oracle program exceptions.
This indicates that a process has encountered an exceptional conndition
In the first place, if an operation seems to be hanging, a wise thing to do is look for an indication of what it's doing -- e.g. in V$SESSION_WAIT or V$SESSION_LONGOPS.
If there were significant foreign key constraints referencing this table, it's not necessarily surprising that it would take time to drop with the cascade constraints option, since that would have to either delete or update rows in other tables.
Anyway, now that you've gotten to an ORA-600 error, there ought to be a trace file on the database server with more information. It may be of interest to you, but most likely you will need to consult Oracle support.