文档解释
ORA-25146: EXTENT MANAGEMENT option already specified
Cause: In CREATE TABLESPACE, the EXTENT MANAGEMENT option was specified more than once.
Action: Remove all but one of the EXTENT MANAGEMENT specifications.
ORA-25146: EXTENT MANAGEMENT option already specified 的意思是：EXTENT MANAGEMENT选项已经被指定。
官方解释
Error: ORA-25146: EXTENT MANAGEMENT option already specified
Text: EXTENT MANAGEMENT option already specified
Cause: An attempt was made to set the EXTENT MANAGEMENT option when it has already been set.
Action: Ensure that the EXTENT MANAGEMENT option has not been set before setting it again.
常见案例
一般处理方法及步骤
1. 确定EXTENT MANAGEMENT选项是否已经指定；
2. 如果是，则不要重复指定它；
3. 如果EXTENT MANAGEMENT选项未指定，请重新指定它；
4. 如果启用了ADB，则必须使用LOCAL时才能指定EXTENT MANAGEMENT选项；
5. 执行ALTER TABLESPACE语句时，指定“EXTENT MANAGEMENT LOCAL”即可；
6. 尝试重新启动数据库，或者使用ALTER TABLESPACE命令重新指定EXTENT MANAGEMENT选项；
7. 若还是无法解决，可以采用卸载并重新安装数据库的方法，重新配置空间管理方式。
