Naoya: Hi,hackers! I have a question about txid_current(). it is "Why does txid_current() assign new transaction-id?". When we executes txid_current() outside of transaction block, it assigns new transaction-id. I guess it doesn't need to assign…

之前版本 PostgreSQL 的 pg_stat_activity 视图的 waiting 字段判断会话是否等待锁资源(通俗地讲, waiting 值为true表示申请不到锁资源处于等待状态),但是并不会给出具体的锁的信息,9.6 版本之后 pg_stat_activity 视图的 waiting 字段被 wait_event_type 和 wait_event 字段取代,这两个字段分别代表等待事件的类型.等待事件名称: SELECT pid, wait_event_type, wait_ev…

FAQ – Automatic Undo Management (AUM) / System Managed Undo (SMU) (Doc ID 461480.1) APPLIES TO: Oracle Database - Enterprise Edition - Version 9.0.1.4 to 18.3.0.0.0 [Release 9.0.1 to 18]Oracle Database Cloud Schema Service - Version N/A and laterOrac…

Transaction recovery: lock conflict caught and ignored环境:RAC 4节点.oracle 11.2.0.4.redhat 5.9 64bit 问题描述: 1.alert.log每隔一段时间就会报如下错误: Transaction recovery: lock conflict caught and ignored Transaction recovery: lock conflict caught and ignored Transactio…

转自:http://www.cnblogs.com/nonato/archive/2013/11/28/3447162.html iOS的对象都继承于NSObject, 该对象有一个方法:retainCount ,内存引用计数. 引用计数在很多技术都用到: window下的COM组件,多线程的信号量,读写锁,思想都一样. (一般情况下: 后面会讨论例外情况)alloc 对象分配后引用计数为1retain 对象的引用计数+1copy copy 一个对象变成新的对象(新内存地址) 引用计数为1 原来…

About Transaction Support Transactions are supported in versions of Ehcache 2.0 and higher. The 2.3.x or lower releases only support XA. However since ehcache 2.4 support for both Global Transactions with xa_strict and xa modes, and Local Transaction…

copy 和 strong(retain) 区别 1. http://blog.csdn.net/itianyi/article/details/9018567 大部分的时候NSString的属性都是copy,那copy与strong的情况下到底有什么区别呢? 比如: @property (retain,nonatomic) NSString *rStr; @property (copy, nonatomic)   NSString *cStr; - (void)test: { NSMutabl…

文档内容   概要   历史记录   详细信息   GL_INTERFACE_CONTROL   GL_INTERFACE_HISTORY   GL_IMPORT_REFERENCES   摘要   Community Discussions   Feedback   参考 适用于: Oracle General Ledger - 版本 11.5 和更高版本 本文档所含信息适用于所有平台 可执行文件:GLLEZL -日记账导入 可执行文件:GLLEZLSRS-通过提交标准请求允许日记账导入程序…

#import <Foundation/Foundation.h> @interface EOCRectangle : NSObject<NSCoding> @property (nonatomic , readonly , assign) float width; @property (nonatomic , readonly , assign) float height; -(id)initWithWidth:(float) width andHeight:(float) he…

全局ID的重要性 体现在sharding的时候 gtid MySQL:global transaction id uuid:universally unique identifier guid:global universally unique identifier 自增id GUID(全局统一标识符) 分库分表都是靠这些id的…

-----获取数据字典SQL(表字段说明)SELECT     [Table Name] = OBJECT_NAME(c.object_id),     [Column Name] = c.name,     [Description] = ex.value FROM     sys.columns c LEFT OUTER JOIN     sys.extended_properties ex ON     ex.major_id = c.object_id     AND ex.minor_…

文档内容   概要   _afrLoop=2068767096030752&id=1591640.1&_afrWindowMode=0&_adf.ctrl-state=qivvl48iu_253#WP_DOCHIST">历史记录   _afrLoop=2068767096030752&id=1591640.1&_afrWindowMode=0&_adf.ctrl-state=qivvl48iu_253#WP_BODY">具体信…

APPLIES TO: Oracle Database Cloud Schema Service - Version N/A and laterOracle Database Exadata Cloud Machine - Version N/A and laterOracle Database Exadata Express Cloud Service - Version N/A and laterOracle Cloud Infrastructure - Database Service -…

SRDC - ORA-22924 or ORA-1555 on LOB data: Checklist of Evidence to Supply (Doc ID 1682707.1) Action Plan 1. Check for LOB Corruption usingsrdc_corrupt_LOB.sql script. Collect the spool output.  脚本检查LOB损坏 --srdc_corrupt_LOB.sql REM srdc_corrupt_LOB.sq…

MySQL 里有很多自增的 id,每个自增 id 都是定义了初始值,然后不停地往上加步长.虽然自然数是没有上限的,但是在计算机里,只要定义了表示这个数的字节长度,那它就有上限.比如,无符号整型 (unsigned int) 是 4 个字节,上限就是 2^32-1 既然自增 id 有上限,就有可能被用完.但是,自增 id 用完了会怎么样呢? 今天这篇文章,我们就来看看 MySQL 里面的几种自增 id,一起分析一下它们的值达到上限以后,会出现什么情况. 表定义自增值 id 说到自增 id,你第一个…

依旧本着尊重原创和劳动者的原则,将地址先贴在前面: http://www.cnblogs.com/nonato/archive/2013/11/28/3447162.html,作者Nonato 以下内容为转载: IOS的对象都继承于NSObject, 该对象有一个方法:retainCount ,内存引用计数. 引用计数在很多技术都用到: window下的COM组件,多线程的信号量,读写锁,思想都一样. (一般情况下: 后面会讨论例外情况)alloc 对象分配后引用计数为1retain 对象的引用…

一 插件简介: 其github地址:https://github.com/li6185377/LKDBHelper-SQLite-ORM 全面支持 NSArray,NSDictionary, ModelClass, NSNumber, NSString, NSDate, NSData, UIColor, UIImage, CGRect, CGPoint, CGSize, NSRange, int,char,float, double, long.. 等属性的自动化操作(插入和查询) 二 实例内容…

原创文章,同步发自作者个人博客,http://www.jasongj.com/sql/mvcc/ PostgreSQL针对ACID的实现机制 事务的实现原理可以解读为RDBMS采取何种技术确保事务的ACID特性.PostgreSQL针对ACID的实现技术如下表所示. ACID 实现技术 原子性(Atomicity) MVCC 一致性(Consistency) 约束(主键.外键等) 隔离性 MVCC 持久性 WAL 从上表可以看到,PostgreSQL主要使用MVCC和WAL两项技术实现ACID特…

Postgresql-xl 调研 来历 这个项目的背后是一家叫做stormDB的公司.整个代买基于postgres-xc.开源版本应该是stormdb的一个分支. In 2010, NTT's Open Source Software Center approached EnterpriseDB to build off of NTT OSSC's experience with a project called RitaDB and EnterpriseDB's experience with…

直接Ctrl+F 搜索你要找的错 # # Simplified Chinese translation for subversion package # This file is distributed under the same license as the subversion package. # # Update to new pot: # msgmerge --update zh_CN.po subversion.pot # # Check translation: # msgfmt…

对pg_locks视图中的virtualxid和transactionid字段感到困惑,经查阅资料,特此在此整理一下学习内容: pg_locks Columns Name Type References Description locktype text   Type of the lockable object: relation, extend, page, tuple, transactionid, virtualxid, object, userlock, or advisory dat…

/* The transaction handle; every session has a trx object which is freed only when the session is freed; in addition there may be session-less transactions rolling back after a database recovery */ typedef struct trx_struct trx_t; struct trx_struct{…

http://www.blogs8.cn/posts/AWif6E4 mariadb的集群也是抄percona的,原理跟PXC一样maridb-cluster就是PXC,原理是一样的.codeship这个公司已经被Percona收购了 PXC的原理 PXC会使用大概是4个端口号3306 数据库对外服务的端口号4444 请求SST SST: 指数据一个镜象传输 xtrabackup , rsync ,mysqldump 4567 : 组成员之间进行沟通的一个端口号4568 : 传输IST用的.相对…

当PostgreSQL需要insert 一条记录的时候,它会把记录头放入xmin,xmax等字段. xmin的值,就是当前的Transaction的TransactionId.这是为了满足MVCC的需要. 跟踪程序进行了解: /* * Allocate the next XID for a new transaction or subtransaction. * * The new XID is also stored into MyProc before returning. * * Note…

Part I-An introduction to transactions If you look at any introductory article or book on J2EE, you'll find only a small portion of the material devoted to the Java Transaction Service (JTS) or the Java Transaction API (JTA). This is not because JTS…

本文转载自 http://www.ietf.org/rfc/rfc3261.txt 中文翻译可参考 http://wenku.baidu.com/view/3e59517b1711cc7931b71654.html Network Working Group J. Rosenberg Request for Comments: 3261 dynamicsoft Obsoletes: 2543 H. Schulzrinne Category: Standards Track Columbia U.…

Skip Headers Oracle Global Finanicals Oracle Global Financials Technical Reference Manual Release 11i         Globalization Flexfields This document describes the globalization flexfields that store certain pieces of country- and region-specific info…

Transactional RFC When using transactional RFC (tRFC), the called function module is executed exactly once in the called system (service property: Exactly Once). The remote system does not have to be available when the RFC client program is executing…

本文内容为转载,重新排版以供学习研究.如有侵权,请联系作者删除. 转载请注明本文出处:Professional C# 6 and .NET Core 1.0 - 37 ADO.NET ------------------------------- What's In This Chapter? Connecting to the database Executing commands Calling stored procedures The ADO.NET object model Wrox.…

Skip Headers Oracle Global Finanicals Oracle Global Financials Technical Reference Manual Release 11i         Globalization Flexfields This document describes the globalization flexfields that store certain pieces of country- and region-specific info…