|Oracle® Database SQL Reference 10g Release 1 (10.1) Part Number
B10759-01 SEQUENCE statement to create a sequence, which is a
database object from which multiple users may generate unique
integers. You can use sequences to automatically generate
primary key values. When a sequence number is generated, the
sequence is incremented, independent of the transaction
committing or rolling back. If two users concurrently increment
the same sequence, then the sequence numbers each user acquires
may have gaps, because sequence numbers are being generated by
the other user. One user can never acquire the sequence number
generated by another user. Once a sequence value is generated by
one user, that user can continue to access that value regardless
of whether the sequence is incremented by another user. Sequence
numbers are generated independently of tables, so the same
sequence can be used for one or for multiple tables. It is
possible that individual sequence numbers will appear to be
skipped, because they were genera