Daniel Westermann's Blog

this is one of: after all these years I really didn’t know this

nested timers in sqlplus:

SYS@orcl> timing start a1
SYS@orcl> timing start   a2
SYS@orcl> timing start     a3
SYS@orcl> timing show
timing for: a3
Elapsed: 00:00:03.39
SYS@orcl> timing stop
timing for: a3
Elapsed: 00:00:07.37
SYS@orcl> timing show
timing for: a2
Elapsed: 00:00:16.55
SYS@orcl> timing stop
timing for: a2
Elapsed: 00:00:20.53
SYS@orcl> timing show
timing for: a1
Elapsed: 00:00:33.45
SYS@orcl> timing stop
timing for: a1
Elapsed: 00:00:36.44

good to know for complex scripts …

another nice features of oracle 12cR1: you may define functions within the sql with clause:

SQL> !cat a.sql
WITH
  FUNCTION f_test ( a NUMBER) RETURN NUMBER
  IS
  BEGIN
    return a * 2;
  END;
select f_test (5) from dual;
/

SQL> @a

 F_TEST(5)
----------
	10

this is particulary useful when you are not allowed to created stored procedures or you are connected to a read only database.