可以将序列高速缓存在内存中,以便于更快地对这些值进行访问。当首次引用序列时,序列值会被填充到高速缓存中。因此会从高速缓存
CYCLE | NOCYCLE :指定在达到最大值或最小值之后,序列是否继续生成值(NOCYCLE是默认选项)
CACHE n | NOCACHE :指定Oracle Server 预先分配并保留在内存中的值的数量(默认情况下,Oracle Server 会高速缓存20 个值)
示例中创建了一个名为DEPT_DEPTID_SEQ的序列,用作DEPARTMENTS 表的DEPARTMENT_ID 列。该序列从120 开始,,不允许高速缓存,也不进行循环。
请勿在序列用于生成主键值时使用CYCLE选项,除非有一个可靠的机制与序列循环相比可以更快地清除旧行。
注:序列与表没有关系。通常,应按序列的预期用途来命名序列。但是,序列可以在任何地方使用,而与其名称无关。

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No,youshouldnotusetherootuserinMySQLforyourproduct.Instead,createspecificuserswithlimitedprivilegestoenhancesecurityandperformance:1)Createanewuserwithastrongpassword,2)Grantonlynecessarypermissionstothisuser,3)Regularlyreviewandupdateuserpermissions

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