what is Sequences in oracle?

                                          Oracle provides an object called a sequence that can generate numeric value.The value generated can have a maxiumum of 38 digit.A sequence can be used to auto generate numeric value.The value generated can have a maximum of 38 digit.
A sequence can be defined to
* Generate number in ascending order or desending order.

* Provide intervals between number .

* Caching of sequence number in memory etc.

The minimum information required for generating numbers using sequence is:-

* The Starting number .

* maximum number that can be generated by a sequence.

*increment value for generating the next number.

                   All this info is provided to oracle at the time of sequence creation .The sql statement used for creating sequence is:-
syntax:-

create sequence sequence_name

[ increment by integer value

  start with integer value

  maxvalue integer value

  minvalue  integer value

  cycle/nocycle

  cache/nocache inter value

 order/noorder ]