Oracle 自动段空间管理(ASSM:auto segment space management)

使用ASSM的一个巨大优势是，位图freelist肯定能够减轻缓冲区忙等待（buffer busy wait）的负担，这个问题在Oracle9i以前的版本里

一. 官网说明

Logical Storage Structures

Oracle.com/docs/cd/E11882_01/server.112/e16508/logical.htm#CNCPT7668

其中有关ASSM 的内容如下：

Logical Space Management

Oracle Database must use logical space management to track and allocate the extents in a tablespace. When a database object requires an extent, the database must have a method of finding and providing it. Similarly, when an object no longer requires an extent, the database must have a method of making the free extent available.