Are there any ways to get sequence number other than getting it for each re

Question

are there any ways to get sequence number other than getting it for each record

Answer 1

CACHE is the number of values Oracle stores in memory. So the first call to NEXTVAL Oracle grabs x numbers; subsequent calls to NEXTVAL are served from memory until they're all gone and them another bunch is grabbed. The attached sql*plus output demonstrates this behaviour.
Note that normally unused numbers in the cache are returned to the data dictionary but in exceptional circumstances (DB crash) they may be lost.
Cheers, APC
SQL> create sequence seq cache 3
  2  /
Sequence created.
SQL> select last_number from user_sequences
  2  where sequence_name = 'SEQ'
  3  /
LAST_NUMBER
          1
SQL> select seq.nextval from dual
  2  /
   NEXTVAL
         1
SQL> select last_number from user_sequences
  2  where sequence_name = 'SEQ'
  3  /
LAST_NUMBER
          4
SQL> select seq.nextval from dual
  2  /
   NEXTVAL
         2
SQL> select last_number from user_sequences
  2  where sequence_name = 'SEQ'
  3  /
LAST_NUMBER
          4
SQL> select seq.nextval from dual
  2  /
   NEXTVAL
         3
SQL> select last_number from user_sequences
  2  where sequence_name = 'SEQ'
  3  /
LAST_NUMBER
          4
SQL> select seq.nextval from dual
  2  /
   NEXTVAL
         4
SQL> select last_number from user_sequences
  2  where sequence_name = 'SEQ'
  3  /
LAST_NUMBER
          7
SQL>