An offline index operation that creates, rebuilds, or drops a clustered index, or rebuilds or drops a nonclustered index, acquires a Schema modification (Sch-M) lock on the table.

• 创建、重新生成或删除聚集索引或者重新生成或删除非聚集索引的脱机索引操作将对表获取架构修改(Sch-M)锁。