关于本地管理的Extent分配使用 Uniform 方式时，如何设置这个数字

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. ==》Uniform Size 160K
2) Segments between 160M and 5120M should be placed in 5120K extent tablespaces. ==>Uniform Size 5M
3) Segments larger than 5120M should be placed in 160M extent tablespaces.  ==>Uniform Size 160M;