DDL (CREATE&DROP INDEX) conflict with DML. More explanation can be found below
Locks and ORA-00054 error
SQL> create table t1 (f1 number);
Table created.
SQL> select * from t1;
no rows selected
SQL> create index t1_idx on t1(f1);
Index created.
SQL> drop index t1_idx;
drop index t1_idx
*
ERROR at line 1:
ORA-00054: resource busy and acquire with NOWAIT specified
SQL> commit;
Commit complete.
SQL> select * from t1;
no rows selected
SQL> select * from t1;
F1
----------
2
SQL> drop index t1_idx;
Index dropped.
SQL> create index t1_idx on t1(f1);
create index t1_idx on t1(f1)
*
ERROR at line 1:
ORA-00054: resource busy and acquire with NOWAIT specified
