f499a1c0_quences_in_Oracle__autonumber___Description
[Parameter] CACHE [Example] CACHE 10 [Description] 
Specify how many values of the sequence Oracle preallocates and keeps in memory for faster access. This integer value can have 28 or fewer digits. The minimum value for this parameter is 2. For sequences that cycle, this value must be less than the number of values in the cycle. You cannot cache more values than will fit in a given cycle of sequence numbers. If a system failure occurs, all cached sequence values that have not been used in committed DML statements are lost. The potential number of lost values is equal to the value of the CACHE parameter.
How to use sequences in Oracle (autonumber)
Description