TRANSACTIONS_PER_ROLLBACK_SEGMENT

Parameter type	Integer
Default value	5
Parameter class	Static
Range of values	1 to operating system-dependent
Real Application Clusters	Multiple instances can have different values.

TRANSACTIONS_PER_ROLLBACK_SEGMENT specifies the number of concurrent transactions you expect each rollback segment to have to handle. The minimum number of rollback segments acquired at startup is TRANSACTIONS divided by the value for this parameter. For example, if TRANSACTIONS is 101 and this parameter is 10, then the minimum number of rollback segments acquired would be the ratio 101/10, rounded up to 11.

You can acquire more rollback segments by naming them in the parameter ROLLBACK_SEGMENTS.