https://social.msdn.microsoft.com/Forums/sqlserver/en-US/dba45618-1d64-4661-891d-74cab09dddf1/deadlock-while-running-multiple-update-statements?forum=sqldatabaseengine Update statement on your table introduces table scan. It means, that SQL Server re…

出自:http://hedengcheng.com/?p=209 两表join的multi update语句,执行结果与预计不一致的分析过程 — multi update结论在实际应用中,不要轻易使用multi update更新,根据join的不同顺序,更新的结果也会发生变化,multi update不是一个有稳定输出的语句,并且输出结果很难理解,最好不用! 整个测试的准备与multi update的处理流程分析,请见下 — T1表DROP TABLE IF EXISTS `t1`; CREAT…

https://www.red-gate.com/simple-talk/sql/learn-sql-server/how-to-track-down-deadlocks-using-sql-server-2005-profiler/ https://social.msdn.microsoft.com/Forums/sqlserver/en-US/41a510cc-0e54-4bfb-92d2-12996abf99f6/help-needed-to-read-the-deadlock-graph…

转载地址:http://lijiejava.iteye.com/blog/790478 有两张表,结构如下: t_item:                          t_bid: id        int                     id        int name    varchar                   name      varchar item_id   int 其中表t_item的主键id是表t_bid的item_id字段的外键.那么在这种情…

有两张表,结构如下: t_item:                          t_bid: id        int                     id        int name    varchar                   name      varchar item_id   int 其中表t_item的主键id是表t_bid的item_id字段的外键.那么在这种情况下,如果删除表t_item中的记录,并且该记录中的id主键被t_bid中的item_i…

"The areal units (zonal objects) used in many geographical studies are arbitrary, modifiable, and subject to the whims and fancies of whoever is doing, or did, the aggregating."                                                                    …

 mongodb 包含众多的原子性操作: 实例: //连接数据库 dbService = connect("localhost:27017"); //选择插入集合 db = dbService.getSiblingDB("jike"); //创建bulk对象用于批量插入 db.update_test.drop(); var bulk = db.update_test.initializeUnorderedBulkOp(); //测试数据 var doc1= { _i…

http://docs.oracle.com/javase/tutorial/essential/concurrency/index.html Concurrency Computer users take it for granted that their systems can do more than one thing at a time. They assume that they can continue to work in a word processor, while othe…

Build 4.0.0.Alpha1 =============================   ** Known BREAKING CHANGES from NH3.3.3.GA to 4.0.0       NHibernate now targets .Net 4.0. Many uses of set types from Iesi.Collections have     now been changed to use corresponding types from the BC…

DB2 Error Messages (Sorted by SQLCODE) DB2 Error Messages (Sorted by SQLCODE) SQLCODE SQLSTATE Description 000 00000 The SQL statement finished successfully.   01xxx The SQL statement finished successfully, but with a warning. +012 01545 The unqualif…