SQL & PL/SQL :: Get Number Of Seconds Between Two Dates (min And Max)?

SQL> SELECT MAX (upd_time), MIN (upd_time), COUNT (serial)
FROM (SELECT * FROM trans
UNION ALL
SELECT * FROM trans_archive);
MAX(UPD_T MIN(UPD_T COUNT(SERIAL)
--------- --------- -------------
23-OCT-13 01-JAN-11 5289261

I need to calculate seconds between MAX (upd_time) and MIN (upd_time) and then calculate trans/sec. Number of trans COUNT (serial).

SQL> desc trans;
Name Null? Type
----------------------------------------- -------- ----------------------------
SERIAL NOT NULL NUMBER(11)
UPD_TIME NOT NULL DATE
MESSAGE NOT NULL VARCHAR2(255 CHAR)
ENTITY_TABLE NOT NULL VARCHAR2(32 CHAR)
ACTION NOT NULL VARCHAR2(12 CHAR)

[code]....

trans_archive the same DDL.

my first try to get intervall between max and min date in secons:

SQL> SELECT EXTRACT (DAY FROM (MAX (UPD_TIME) - MIN (UPD_TIME))) * 24 * 60 * 60
+ EXTRACT (HOUR FROM (MAX (UPD_TIME) - MIN (UPD_TIME))) * 60 * 60
+ EXTRACT (MINUTE FROM (MAX (UPD_TIME) - MIN (UPD_TIME))) * 60
+ EXTRACT (SECOND FROM (MAX (UPD_TIME) - MIN (UPD_TIME)))
DELTA
FROM (SELECT * FROM TRANS
UNION ALL
SELECT * FROM TRANS_ARCHIVE);
SELECT EXTRACT (DAY FROM (MAX (UPD_TIME) - MIN (UPD_TIME))) * 24 * 60 * 60
*
ERROR at line 1:
ORA-30076: invalid extract field for extract source