取决于存储的segment的大小。根据Bhaskar Himatsingka的HOW TO STOP DEFRAGMENTING AND START LIVING: THE DEFINITIVE
WORD ON FRAGMENTATION一文,建议是
1) Segments smaller than 160M should be placed in 160K extent tablespaces.
2) Segments between 160M and 5120M should be placed in 5120K extent tablespaces.
3) Segments larger than 5120M should be placed in 160M extent tablespaces.