Premature optimization is the root of all evil in programming. C.A.R. Hoare
The DUAL table is a special one-row, one-column table present by default in Oracle and other database installations. The sysdate returns the current date from the oracle database server.
SELECT sysdate from dual;
The to_char funcation format the date.
SELECT TO_CHAR(SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "NOW" FROM DUAL;