分别创建两个sequence实验对象。 SQL> create sequence seq_nocache nocache; Sequence created SQL> create sequence seq_cache cache 3; Sequence created 我们先对nocache对象进行实验。我们选择autotrace工具,进行三次调用操作,来观察各种资源使用情况。 --第一次调用;
CACHENOCACHE NOCACHECACHENOCACHEORDERto guarantee that sequence numbers are generated in order of request. This clause is useful if you are using the sequence numbers as timestamps. Guaranteeing order is usually not important for sequences used to generate primary keys. ORDERNOORDERif you do not...
CACHENOCACHE NOCACHECACHENOCACHEORDERto guarantee that sequence numbers are generated in order of request. This clause is useful if you are using the sequence numbers as timestamps. Guaranteeing order is usually not important for sequences used to generate primary keys. ORDERNOORDER...
oracle修改sequence最大最小值_oracle取最大值的记录 seq_name [start with n] [minvalue n | nomainvalue] [maxvalue n | nomaxvalue] [cache n | ncache 2.7K60 扫码 添加站长 进交流群 领取专属10元无门槛券 手把手带您无忧上云 相关资讯 ...
1、序列CACHE设置对性能的影响1.1 序列的cache为0SQL> select sid from v$mystat where rownum=1; SID- 52SQL> SET timing ON;SQL> -清除数据SQL> TRUNCATE TABLE tb_seq;表已截掉。已用时间: 00: 00: 00.00SQL> -删除序列SQL> DROP SEQUENCE seq_test;序列已丢弃。已用时间: 00: 00: 00.00SQL> -...
Kafka中sequence IO、PageCache、SendFile的应用详解 大家都知道Kafka是将数据存储于磁盘的,而磁盘读写性能往往很差,但Kafka官方测试其数据读写速率能达到600M/s,那么为什么Kafka性能会这么高呢? 首先producer往broker发送消息时,采用batch的方式即批量而非一条一条的发送,这种方式可以有效降低网络IO的请求次数,提升...
在Oracle中,用如下SQL命令创立了一种序列:CREATE SEQUENCE my_seqSTART WITH 394INCREMENT BY 12NOMINVALUENOMAXVALUENOCYCLENOCACHE;顾客执行涉及my_seq.NEXTVAL旳SQL语句三次,然后执行涉及my_seq.CURRVAL旳SQL语句四次,请问序列my_seq旳目前值是(选一项) 答案 B 解析 null 本题来源 题目:在Oracle中,用如下SQL命...
StartTimedatetime该事件(如果存在)的启动时间。14是 TextDatantext正在缓存的 SQL 代码的文本。1是 TransactionIDbigint系统分配的事务 ID。4是 XactSequencebigint用于说明当前事务的标记。50是 另请参阅 sp_trace_setevent (Transact-SQL) SP:CacheMiss 事件类...
SQL> alter sequence PDABASE.SQ_T_PDAM_POSITION cache 20; 通过AWR分析思路如下: 参考:http://www.itpub.net/thread-1621524-1-1.html 1、DB Time相比平时明显是异常的 2、通过Load Profile节看到对于当前系统而言每秒的请求数是不正常的 3、继续分析报告,从Top 5中看到排在第一的等待事件是row cache lock...
Sequences PL/SQL packages, procedures and functions (applies only to TimesTen 11gand later) To grant privileges on a particular element, right-click the name of the element and selectPrivileges>Grant. In theUserspull-down menu of theGrantdialog box, select the user that you want to grant obj...