CREATE_BITMAP_AREA_SIZE
Values:Operating system dependent
Default:8 Mb
Specifies the amount of memory Oracle allocates for bitmap creation, with a default value of 8 Mb. A larger value usually leads to faster index creation. If cardinality is very small, a small value can be set for this parameter. For example, if cardinality is only 2, the value can be in kilobytes rather than megabytes. As a general rule, the higher the cardinality, the more memory is needed for optimal performance.