SQL> startup
ORACLE instance started.
Total System Global Area 97588504 bytes
Fixed Size 451864 bytes
Variable Size 33554432 bytes
Database Buffers 62914560 bytes
Redo Buffers 667648 bytes
Database mounted.
Database opened.
SQL> select count(*) from t;
select count(*) from t
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> create table t as select * from dba_users;
Table created.
SQL> select count(*) from t;
COUNT(*)
----------
12
SQL> startup
ORACLE instance started.
Total Sys