You can create and rebuild indexes online. This enables you to update base tables at the same time you are building or rebuilding indexes on that table. You can perform DML operations while the index build is taking place, but DDL operations are not allowed.
如果建立索引时指定关键字online,那么只会在表上加一个共享锁,仅不允许变更表的定义。
但可以对数据进行修改。