单项选择题
According to your backup strategy， you performed an incremental level 0 backup of yourdatabase. Which statement regarding this backup is true？（）
A.The backup is similar to image copy. B.The backup contains all used data blocks. C.The backup contains only unused data blocks. D.The backup contains all data blocks changed since the last incremental level 1 backup.
单项选择题 WhichstatementregardingthecontentsoftheV$PARAMETERviewistrue？（）
多项选择题 Whichthreestatementsarecorrectabouttemporarytables？（）
单项选择题 TheUNDO_RETENTIONparameterinyourdatabaseissetto1000andundoretentionisnotguaranteed.Whichstatementregardingretentionofundodataiscorrect？（）
