在介绍新的 CSS 属性 contain 之前,读者首先需要了解什么是页面的重绘与重排. 之前已经描述过很多次了,还不太了解的可以先看看这个提高 CSS 动画性能的正确姿势. OK,下面进入本文正题, contain 为何? contain 属性允许我们指定特定的 DOM 元素和它的子元素,让它们能够独立于整个 DOM 树结构之外.目的是能够让浏览器有能力只对部分元素进行重绘.重排,而不必每次都针对整个页面. The contain property allows an author to in
Identity Column in SQL Server If a column is marked as an identity column, then the values for this column are automatically generated, when you insert a new row into the table. The following, create table statement marks PersonId as an identity colu
Gap Locks 区间锁 1. 区间锁不能用于语句锁定记录使用一个唯一索引来搜索一个唯一的记录 2.READ COMMITTED 没有区间锁 区间锁是一个锁在一个在index记录间的区间,或者一个lock 在gap 在第一个前或者最后一个index recoed 之后, 比如,SELECT c1 FOR UPDATE FROM t WHERE c1 BETWEEN 10 and 20; 会阻止其他事务插入15的值到列t.c1, 无论这里已经有任何这样的值在列里, 因为区间在所有存在的值在范围内
http://dev.mysql.com/doc/refman/5.0/en/innodb-record-level-locks.html InnoDB has several types of record-level locks including record locks, gap locks, and next-key locks. For information about shared locks, exclusive locks, and intention locks, see
InnoDB has several types of record-level locks including record locks, gap locks, and next-key locks. For information about shared locks, exclusive locks, and intention locks, see Section 14.3.5.3, “InnoDB Lock Modes”. InnoDB有几种行级锁类型, 包括 record 锁, ga
###########1 1.查看备库的scn ⚠️如果控制文件,数据文件,数据文件头部的scn不一致,需要根据日志中的gap的起始sequence# 找到对应的scn col current_scn for a999999999; select current_scn from v$database; 2.查看主库在断点后是否添加数据文件 select file#,name, from v$datafile where current_change#>=备库查得的断电处scn: 3.备库停
理论背景 当redo data 传送发生中断时就会产生redo gap.当redo 传送恢复正常以后,redo transport service 会自动检测redo gap并发送缺失的redo 到destination.解决redo gap的时间与gap 的数量和网络有一定的关系. Gap越少,网络越好,解决gap就会越快. 手工解决 Gap 问题 在Oracle 11g里,Data Guard 切换多了一个新的功能:flush redo.SQL> alter system flush red
autocommit 隔离级别 https://www.ibm.com/developerworks/cn/opensource/os-mysql-transaction-isolation-levels-and-locks/index.html MySQL 事务隔离级别和锁 事务特性和 InnoDB 锁 2019 年 8 月 26 日发布 事务及其特性 IBM Compose for MySQL IBM Cloud 上提供的 Compose for MySQL 数据库服务可以帮助您更好
问题: Springboot启动报错: Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.
环境:Oracle 11.2.0.4 DG 故障现象: 客户在备库告警日志中发现GAP sequence提示信息: Mon Nov 21 09:53:29 2016 Media Recovery Waiting for thread 1 sequence 12034 Fetching gap sequence in thread 1, gap sequence 12034-12078 Mon Nov 21 09:55:20 2016 FAL[client]: Failed to request
Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its corresponding column number. For example: A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28 Credits:Special thanks to @ts for addi
Given a positive integer, return its corresponding column title as appear in an Excel sheet. For example: 1 -> A 2 -> B 3 -> C ... 26 -> Z 27 -> AA 28 -> AB Credits:Special thanks to @ifanchu for adding this problem and creating all test
今天在使用mysql数据库查找数据的时候报错,错误信息如下: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'dd' in 'where clause' at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newI
