Today a coworker ask me about an ora-12988 error when he was modifiying a table, look for error;
admin> oerr ora 12988
12988, 00000, “cannot drop column from table owned by SYS”
// *Cause: An attempt was made to drop a column from a system table.
// *Action: This action is not allowed
The error is clearly, of course, it is not a good idea create table or any object in sys schema but many times we need create temporary tables. In this case the problem was;
SQL> alter table copy_of_objects drop column object_id;
alter table unodos drop column object_id
ERROR at line 1:
ORA-12988: cannot drop column from table owned by SYS
Oracle must implemented this error like autodefense of views or tables property of sys schema. The solution was drop the table.
HTH – Antonio NAVARRO