在oracle创建用户的时候若没有分配表空间，则默认为什么表空间

USERS tablespace

  SYSTEM 表空间，以下是从 oracle10g document 中节选，以供参考

This tablespace is used to store permanent user objects and data。 Like the TEMP tablespace, every database should have a tablespace for permanent user data that is assigned to users。

   Otherwise, user objects will be created in the SYSTEM tablespace, which is not good practice。 In the preconfigured database, USERS is assigned the default tablespace, and space for all objects created by non-system users comes from this tablespace。

   For system users, the default permanent tablespace remains SYSTEM。

This tablespace 是指 USERS tablespace。