concepts中关于sort segment的描述有这么一段是变化的：
（9i）You can manage space for sort operations more efficiently by designating

temporary tablespaces exclusively for sorts. Doing so effectively eliminates

serialization of space management operations involved in the allocation and

deallocation of sort space.

A temporary tablespace can be used only for sort segments. A temporary tablespace

is not the same as a tablespace that a user designates for temporary segments,

which can be any tablespace available to the user. No permanent schema objects can

reside in a temporary tablespace

（10g）You can manage space for sort operations more efficiently by designating one or more

temporary tablespaces exclusively for sorts. Doing so effectively eliminates

serialization of space management operations involved in the allocation and

deallocation of sort space. A single SQL operation can use more than one temporary

tablespace for sorting. For example, you can create indexes on very large tables, and

the sort operation during index creation can be distributed across multiple tablespaces.

One or more temporary tablespaces can be used only for sort segments. A temporary

tablespace is not the same as a tablespace that a user designates for temporary

segments, which can be any tablespace available to the user. No permanent schema

objects can reside in a temporary tablespace.

从描述变化可以看出9i sort segments只使用1个表空间，但10g中可能使用1个或多个表空间