Which two statements about creating constraints are true?（） Constraint names must start with SYS_C。 All constraints must be defines at the column level.。 Constraints can be created after the table is created.。 Constraints can be created at the same time the table is created.。 Information about constraints is found in the VIEW_CONSTRAINTS dictionary view.。
使用工具可能产生的问题不包括（） 故障误报。 流程固化后不够灵活。 系统资源占用。 增加开发成本。
Given a complete loss of your database， in what order would you need to perform the following RMAN operations to restore it？（） a. restore controlfile b. restore database c. restore spfile d. recover database e. alter database open f. alter database open resetlogs b， a， c， d， e。 a， c， b， d， f。 c， a， b， d， e。 c， a， b， d， f。 e， a， b， d， c。
凡尔赛一华盛顿体系形成后，法国元帅福煦曾预言：“这不是和平，这是20年的休战。”这主要是因为（）。 资本主义大国与殖民地半殖民地的矛盾依然存在。 两种社会制度之间的矛盾终将激化。 没有消除各大国之间的矛盾，却埋下了更大冲突的种子。 法西斯专政的建立。
Which statement is true regarding the retention policy for the incidents accumulated in the AutomaticDiagnostic Repository (ADR)?（） The incident metadata is purged when the problem is resolved and the DBA closes the SR。 The incident files and dumps are not retained in the ADR for the manually created incidents。 The incident files are retained but the incident metadata is purged when the problem is resolved and the DBA closes the SR。 The default setting is for one year after which the incident metadata is purged from the ADR and the files are retained for one month。
家族企业最显著的特征是（）。
