江南歌词oracle表空间uniform，创建表空间时UNIFORMSIZE的通俗含义
拉肚子吃什么水果（翻译）
本⽂讨论创建表空间时，采⽤AutoAllocate扩展模式还是Uniform扩展模式.
官⽅⽂档解释如下：
号的多音字组词If you expect the tablespace to contain objects of varying sizes
requiring many extents with different extent sizes, then AUTOALLOCATE
is the best choice. AUTOALLOCATE is also a good choice if it is not
important for you to have a lot of control over space allocation and
deallocation, because it simplifies tablespace management. Some space
may be wasted with this setting, but the benefit of having Oracle
Database manage your space most likely outweighs this drawback.
如果你希望你的表空间包含多种⼤⼩的扩展对象(扩展段)，AutoAllocate 就是最好的选择。⽽且当你不怎么关⼼表空间的分配和回
收，AutoAllocate也是⼀个很好的选择，因为它简化了表空间管理。当然当你采⽤这样的配置时，⼀些空间可能存在浪费，但是让Oracle 数据库管理你的表空间将会让你获益更多(精⼒⽅⾯)。
If you want exact control over unused space, and you can predict
exactly the space to be allocated for an object or objects and the
number and size of extents, then UNIFORM is a good choice.
如果你想精细控制未分配的空间，同时你能准确的估计数据对象的数量和分配给数据对象使⽤空间的⼤⼩，那么Uniform就是⼀个很好的选择。
■
With AUTOALLOCATE extent management, Oracle uses the INITIAL setting
to optimize the number of extents allocated. Extents of 64K, 1M, 8M,
and 64M can be allocated. During segment creation, the system chooses
the greatest of these four sizes that is equal to or smaller than
INITIAL, and allocates as many extents of that size as are needed to
reach the INITIAL setting. For example, if you set INITIAL to 4M, then
the database creates four 1M extents.
采⽤AutoAllocate扩展管理，Oracle使⽤初始化设置来优化需要分配的扩展空间。扩展空间的选择有64K，1M，8M，64M。当进⾏扩展段创建时，初始，系统会从四个可选项中挑选出⼩于等于初始值的最⼤项，然后不断从四个可选项中选择合适项，直到达到初始设定值。⽐如你设定的初始值为4M，那么数据库将会创建4个1M的扩展。
■ For UNIFORM extent management, the number of extents is determined
from initial segment size and the uniform extent size specified at
tablespace creation time. For example, in a uniform locally managed
tablespace with 1M extents, if you specify an INITIAL value of 5M,
then Oracle creates five 1M extents. Consider this comparison: With
AUTOALLOCATE, if you set INITAL to 72K, then the initial segment size
will be 128K (greater than INITIAL). The database cannot allocate an
extent smaller than 64K, so it must allocate two 64K extents. If you
set INITIAL to 72K with a UNIFORM extent size of 24K, then the
军校2019招生database will allocate three 24K extents to equal 72K.
对于采⽤Uniform扩展管理，扩展段⼤⼩取决于，创建数据库时所设定的初始段⼤⼩和统⼀扩展段⼤⼩。举个例⼦，在Uniform扩展模式下设定每次增长1M，如果你指定初始值为5M，那么Oracle将会创建5个1M。现在我们来⽐较⼀下：采⽤AutoAllocate扩展模式，假设初始值为72K，那么最终Oracle数据库设置的段⼤⼩为128K(⽐初始值⼤)。因为数据库中没有扩展段⼩于64K，所以必须分配两个64K的扩展段。如果采⽤Uniform扩展模式，初始值仍为72K，每次统⼀扩展⼤⼩为24K，那么数据库将会分配3个24K⼤⼩的扩展，因为
汽车有哪些品牌支付宝好友3*24K=72K；
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