参考MOS文章How to Shrink the datafile of Undo Tablespace (文档 ID 268870.1) 操作步骤如下 Create a new undo tablespace with a smaller size: {代码...} Set the new tablespace as the undo tablespace to be used: {代码...} Drop the old undo tablespace: {代码...} 可能碰到的问题 如果要drop的undo tablespa...