Oracle 11G OCP 1Z0-052 25

（25）Which three operations require undo data? (Choose three.)

A.committing a transaction

B.flashing back a transaction

C.recovering a failed transaction

D.running a read-consistent query

E.changing a tablespace status from READ ONLY to READ WRITE

答案：（B、C、D）

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/17013648/viewspace-1176656/，如需轉載，請註明出處，否則將追究法律責任。