You work as a database administrator for Certkiller .com. Your database is configured for automatic undo management. UNDO_RETENTION is set to 3 hours. You want to flash back a table that was created last year. How far back can the flashback query go? () 3 hours。 6 months。 until last year。 until last commit。 until the point when the undotablespacewas refreshed。 until the database is shut down and the memory erased。
根据原型与最终产品之间的关系,原型开发分类包括() 抛弃式。 演化史。 瀑布是。 增量。
似亲孢子
电子商务法的基本原则?
25号变压器油()适用于()以上。
对于公路工程采用新材料、新工艺、新设备时,其计价方法有()。