sybase锁机制以及死锁避免

在数据库实现中,通过锁定机制控制数据库的并发访问,保证数据库访问的正确性。根据定义:

锁定是一种并发控制机制:它可以确保数据在同一事务中和不同事务之间保持一致。在多用户环境中,由于几个用户可能会在同一时间使用同一数据,因此需要锁定功能。

 sybase锁分类

按照锁性质可以分为共享锁,排他锁。当在数据库事务中,读取信息时,会对数据库添加共享锁。当修改信息时,会添加排他锁。

按照锁的粒度,可以分为行锁,页锁,表锁等。

 sybase隔离级别

sybase分为0,1,2,3四个隔离级别。

0 读取未提交的,允许事务读取未提交的数据更改,排他锁在对数据库进行写操作后立即释放,不会持有到事务提交或回滚。
1 读取已提交的,仅允许事务读取已提交的数据更改,排他锁持有到事务提交或回滚,但共享锁在加载数据到内存后立即释放。
2 可重复读取事务可重复同一查询,事务读取过的任何行都不会被更新或删除,排它锁和共享锁都会持有到事务结束,查询结果集不可以删除和修改,但是可以插入。
3 可串行化读取事务可重复同一查询,且得到完全相同的结果。不能插入任何将出现在结果集中的行,排它锁和共享锁都会持有到事务结束,查询结果集不可以增删改。

可以使用select @@isolation语句查看数据库的隔离级别。

sybase数据库通常隔离界别设置为1,值得注意的是使用WAS通过jdbc连接数据库上,经常会将隔离级别提升为2。在使用E-SQL编译时,通常将隔离级别提升为3。

 sybase死锁

sybase数据库出现死锁,即处于死锁中的各事务,都持有锁,但又都在等待其他锁,从而组成一个环,造成死锁。

 

 

 

img.sootoo.com/user/data/36489/
img.sootoo.com/user/data/36489/
img.sootoo.com/user/data/36200/
img.sootoo.com/user/data/36201/
img.sootoo.com/user/data/36202/
img.sootoo.com/user/data/36204/
img.sootoo.com/user/data/36205/
img.sootoo.com/user/data/36206/
img.sootoo.com/user/data/36207/
img.sootoo.com/user/data/36208/
img.sootoo.com/user/data/36209/
img.sootoo.com/user/data/36340/
img.sootoo.com/user/data/36341/
img.sootoo.com/user/data/36342/
img.sootoo.com/user/data/36343/
img.sootoo.com/user/data/36344/
img.sootoo.com/user/data/36345/
img.sootoo.com/user/data/36346/
img.sootoo.com/user/data/36347/
img.sootoo.com/user/data/36348/
img.sootoo.com/user/data/36349/
img.sootoo.com/user/data/36350/
img.sootoo.com/user/data/36351/
img.sootoo.com/user/data/36352/
img.sootoo.com/user/data/36353/
img.sootoo.com/user/data/36354/
img.sootoo.com/user/data/36371/
img.sootoo.com/user/data/36372/
img.sootoo.com/user/data/36373/
img.sootoo.com/user/data/36374/
img.sootoo.com/user/data/36375/
img.sootoo.com/user/data/36376/
img.sootoo.com/user/data/36377/
img.sootoo.com/user/data/36378/
img.sootoo.com/user/data/36379/
img.sootoo.com/user/data/36381/
img.sootoo.com/user/data/36382/
img.sootoo.com/user/data/36384/
img.sootoo.com/user/data/36385/
img.sootoo.com/user/data/36386/
img.sootoo.com/user/data/36387/
img.sootoo.com/user/data/36388/
img.sootoo.com/user/data/36389/
img.sootoo.com/user/data/36390/
img.sootoo.com/user/data/36391/
img.sootoo.com/user/data/36392/
img.sootoo.com/user/data/36393/
img.sootoo.com/user/data/36394/
img.sootoo.com/user/data/36395/
img.sootoo.com/user/data/36396/
img.sootoo.com/user/data/36397/
img.sootoo.com/user/data/36398/
img.sootoo.com/user/data/36399/
img.sootoo.com/user/data/36400/
img.sootoo.com/user/data/36402/
img.sootoo.com/user/data/36403/
img.sootoo.com/user/data/36404/
img.sootoo.com/user/data/36405/
img.sootoo.com/user/data/36406/
img.sootoo.com/user/data/36407/
img.sootoo.com/user/data/36408/
img.sootoo.com/user/data/36409/
img.sootoo.com/user/data/36411/
img.sootoo.com/user/data/36412/
img.sootoo.com/user/data/36413/
img.sootoo.com/user/data/36414/
img.sootoo.com/user/data/36415/
img.sootoo.com/user/data/36416/
img.sootoo.com/user/data/36417/
img.sootoo.com/user/data/36418/
img.sootoo.com/user/data/36419/
img.sootoo.com/user/data/36420/
img.sootoo.com/user/data/36421/
img.sootoo.com/user/data/36422/
img.sootoo.com/user/data/36423/
img.sootoo.com/user/data/36426/
img.sootoo.com/user/data/36427/
img.sootoo.com/user/data/36428/
img.sootoo.com/user/data/36429/
img.sootoo.com/user/data/36430/
img.sootoo.com/user/data/36431/
img.sootoo.com/user/data/36432/
img.sootoo.com/user/data/36433/
img.sootoo.com/user/data/36434/
img.sootoo.com/user/data/36437/
img.sootoo.com/user/data/36438/
img.sootoo.com/user/data/36439/
img.sootoo.com/user/data/36440/
img.sootoo.com/user/data/36441/
img.sootoo.com/user/data/36442/
img.sootoo.com/user/data/36443/
img.sootoo.com/user/data/36444/
img.sootoo.com/user/data/36445/
img.sootoo.com/user/data/36446/
img.sootoo.com/user/data/36447/
img.sootoo.com/user/data/36448/
img.sootoo.com/user/data/36449/
img.sootoo.com/user/data/36450/
img.sootoo.com/user/data/36451/
img.sootoo.com/user/data/36452/
img.sootoo.com/user/data/36453/
img.sootoo.com/user/data/36454/
img.sootoo.com/user/data/36455/
img.sootoo.com/user/data/36456/
img.sootoo.com/user/data/36457/
img.sootoo.com/user/data/36459/
img.sootoo.com/user/data/36460/
img.sootoo.com/user/data/36461/
img.sootoo.com/user/data/36462/
img.sootoo.com/user/data/36463/
img.sootoo.com/user/data/36464/
img.sootoo.com/user/data/36465/
img.sootoo.com/user/data/36466/
img.sootoo.com/user/data/36467/
img.sootoo.com/user/data/36468/
img.sootoo.com/user/data/36469/
img.sootoo.com/user/data/36470/
img.sootoo.com/user/data/36471/
img.sootoo.com/user/data/36472/
img.sootoo.com/user/data/36473/
img.sootoo.com/user/data/36474/
img.sootoo.com/user/data/36475/
img.sootoo.com/user/data/36476/
img.sootoo.com/user/data/36477/
img.sootoo.com/user/data/36478/
img.sootoo.com/user/data/36479/
img.sootoo.com/user/data/36480/
img.sootoo.com/user/data/36481/
img.sootoo.com/user/data/36482/
img.sootoo.com/user/data/36483/
img.sootoo.com/user/data/36485/
img.sootoo.com/user/data/36486/
img.sootoo.com/user/data/36487/
img.sootoo.com/user/data/36488/
img.sootoo.com/user/data/36210/
img.sootoo.com/user/data/36210/
img.sootoo.com/user/data/36211/
img.sootoo.com/user/data/36413/
img.sootoo.com/user/data/36414/
img.sootoo.com/user/data/36415/
img.sootoo.com/user/data/36212/
img.sootoo.com/user/data/36215/
img.sootoo.com/user/data/36216/
img.sootoo.com/user/data/36217/
img.sootoo.com/user/data/36218/
img.sootoo.com/user/data/36220/
img.sootoo.com/user/data/36222/
img.sootoo.com/user/data/36223/
img.sootoo.com/user/data/36224/
img.sootoo.com/user/data/36225/
img.sootoo.com/user/data/36226/
img.sootoo.com/user/data/36227/
img.sootoo.com/user/data/36228/
img.sootoo.com/user/data/36229/
img.sootoo.com/user/data/36230/
img.sootoo.com/user/data/36231/
img.sootoo.com/user/data/36232/
img.sootoo.com/user/data/36235/
img.sootoo.com/user/data/36236/
img.sootoo.com/user/data/36238/
img.sootoo.com/user/data/36239/
img.sootoo.com/user/data/36240/
img.sootoo.com/user/data/36242/
img.sootoo.com/user/data/36212/
img.sootoo.com/user/data/36247/
img.sootoo.com/user/data/36248/
img.sootoo.com/user/data/36249/
img.sootoo.com/user/data/36250/
img.sootoo.com/user/data/36251/
img.sootoo.com/user/data/36252/
img.sootoo.com/user/data/36253/
img.sootoo.com/user/data/36254/
img.sootoo.com/user/data/36255/
img.sootoo.com/user/data/36257/
img.sootoo.com/user/data/36260/
img.sootoo.com/user/data/36262/
img.sootoo.com/user/data/36263/
img.sootoo.com/user/data/36264/
img.sootoo.com/user/data/36265/
img.sootoo.com/user/data/36266/
img.sootoo.com/user/data/36267/
img.sootoo.com/user/data/36268/
img.sootoo.com/user/data/36269/
img.sootoo.com/user/data/36270/
img.sootoo.com/user/data/36271/
img.sootoo.com/user/data/36273/
img.sootoo.com/user/data/36274/
img.sootoo.com/user/data/36275/
img.sootoo.com/user/data/36276/
img.sootoo.com/user/data/36277/
img.sootoo.com/user/data/36278/
img.sootoo.com/user/data/36279/
img.sootoo.com/user/data/36280/
img.sootoo.com/user/data/36282/
img.sootoo.com/user/data/36283/
img.sootoo.com/user/data/36284/
img.sootoo.com/user/data/36285/
img.sootoo.com/user/data/36286/
img.sootoo.com/user/data/36287/
img.sootoo.com/user/data/36289/
img.sootoo.com/user/data/36290/
img.sootoo.com/user/data/36291/
img.sootoo.com/user/data/36292/
img.sootoo.com/user/data/36293/
img.sootoo.com/user/data/36295/
img.sootoo.com/user/data/36299/
img.sootoo.com/user/data/36300/
img.sootoo.com/user/data/36302/
img.sootoo.com/user/data/36303/
img.sootoo.com/user/data/36304/
img.sootoo.com/user/data/36305/
img.sootoo.com/user/data/36306/
img.sootoo.com/user/data/36307/
img.sootoo.com/user/data/36308/
img.sootoo.com/user/data/36309/
img.sootoo.com/user/data/36310/
img.sootoo.com/user/data/36311/
img.sootoo.com/user/data/36312/
img.sootoo.com/user/data/36313/
img.sootoo.com/user/data/36314/
img.sootoo.com/user/data/36315/
img.sootoo.com/user/data/36316/
img.sootoo.com/user/data/36317/
img.sootoo.com/user/data/36319/
img.sootoo.com/user/data/36320/
img.sootoo.com/user/data/36321/
img.sootoo.com/user/data/36322/
img.sootoo.com/user/data/36323/
img.sootoo.com/user/data/36325/
img.sootoo.com/user/data/36326/
img.sootoo.com/user/data/36327/
img.sootoo.com/user/data/36328/
img.sootoo.com/user/data/36329/
img.sootoo.com/user/data/36330/
img.sootoo.com/user/data/36331/
img.sootoo.com/user/data/36332/
img.sootoo.com/user/data/36333/
img.sootoo.com/user/data/36334/
img.sootoo.com/user/data/36335/
img.sootoo.com/user/data/36336/
img.sootoo.com/user/data/36337/
img.sootoo.com/user/data/36338/
img.sootoo.com/user/data/36339/
img.sootoo.com/user/data/36340/
img.sootoo.com/user/data/36341/
img.sootoo.com/user/data/36342/
img.sootoo.com/user/data/36344/
img.sootoo.com/user/data/36345/
img.sootoo.com/user/data/36348/
img.sootoo.com/user/data/36349/
img.sootoo.com/user/data/36350/
img.sootoo.com/user/data/36351/
img.sootoo.com/user/data/36353/
img.sootoo.com/user/data/36354/
img.sootoo.com/user/data/36371/
img.sootoo.com/user/data/36372/
img.sootoo.com/user/data/36373/
img.sootoo.com/user/data/36374/
img.sootoo.com/user/data/36376/
img.sootoo.com/user/data/36377/
img.sootoo.com/user/data/36378/
img.sootoo.com/user/data/36379/
img.sootoo.com/user/data/36381/
img.sootoo.com/user/data/36382/
img.sootoo.com/user/data/36384/
img.sootoo.com/user/data/36385/
img.sootoo.com/user/data/36386/
img.sootoo.com/user/data/36387/
img.sootoo.com/user/data/36388/
img.sootoo.com/user/data/36389/
img.sootoo.com/user/data/36390/
img.sootoo.com/user/data/36391/
img.sootoo.com/user/data/36392/
img.sootoo.com/user/data/36393/
img.sootoo.com/user/data/36394/
img.sootoo.com/user/data/36395/
img.sootoo.com/user/data/36396/
img.sootoo.com/user/data/36398/
img.sootoo.com/user/data/36399/
img.sootoo.com/user/data/36400/
img.sootoo.com/user/data/36402/
img.sootoo.com/user/data/36403/
img.sootoo.com/user/data/36404/
img.sootoo.com/user/data/36405/
img.sootoo.com/user/data/36406/
img.sootoo.com/user/data/36407/
img.sootoo.com/user/data/36409/
img.sootoo.com/user/data/36411/
img.sootoo.com/user/data/36412/
img.sootoo.com/user/data/36413/
img.sootoo.com/user/data/36414/
img.sootoo.com/user/data/36494/
img.sootoo.com/user/data/36496/
img.sootoo.com/user/data/36497/
img.sootoo.com/user/data/36499/
img.sootoo.com/user/data/36500/
img.sootoo.com/user/data/36501/
img.sootoo.com/user/data/36502/
img.sootoo.com/user/data/36503/
img.sootoo.com/user/data/36504/
img.sootoo.com/user/data/36505/
img.sootoo.com/user/data/36506/
img.sootoo.com/user/data/36507/
img.sootoo.com/user/data/36509/
img.sootoo.com/user/data/36510/
img.sootoo.com/user/data/36511/
img.sootoo.com/user/data/36512/
img.sootoo.com/user/data/36513/
img.sootoo.com/user/data/36514/
img.sootoo.com/user/data/36515/
img.sootoo.com/user/data/36516/
img.sootoo.com/user/data/36517/
img.sootoo.com/user/data/36518/
img.sootoo.com/user/data/36519/
img.sootoo.com/user/data/36520/
img.sootoo.com/user/data/36521/
img.sootoo.com/user/data/36522/
img.sootoo.com/user/data/36523/
img.sootoo.com/user/data/36524/
img.sootoo.com/user/data/36525/
img.sootoo.com/user/data/36526/
img.sootoo.com/user/data/36527/
img.sootoo.com/user/data/36528/
img.sootoo.com/user/data/36529/
img.sootoo.com/user/data/36530/
img.sootoo.com/user/data/36531/
img.sootoo.com/user/data/36532/
img.sootoo.com/user/data/36534/
img.sootoo.com/user/data/36535/
img.sootoo.com/user/data/36536/
img.sootoo.com/user/data/36537/
img.sootoo.com/user/data/36538/
img.sootoo.com/user/data/36539/
img.sootoo.com/user/data/36540/
img.sootoo.com/user/data/36541/
img.sootoo.com/user/data/36542/
img.sootoo.com/user/data/36543/
img.sootoo.com/user/data/36545/
img.sootoo.com/user/data/36546/
img.sootoo.com/user/data/36547/
img.sootoo.com/user/data/36548/
img.sootoo.com/user/data/36549/
img.sootoo.com/user/data/36550/
img.sootoo.com/user/data/36551/
img.sootoo.com/user/data/36552/
img.sootoo.com/user/data/36553/
img.sootoo.com/user/data/36554/
img.sootoo.com/user/data/36555/
img.sootoo.com/user/data/36556/
img.sootoo.com/user/data/36557/
img.sootoo.com/user/data/36558/
img.sootoo.com/user/data/36559/
img.sootoo.com/user/data/36560/
img.sootoo.com/user/data/36561/
img.sootoo.com/user/data/36562/
img.sootoo.com/user/data/36563/
img.sootoo.com/user/data/36564/
img.sootoo.com/user/data/36565/
img.sootoo.com/user/data/36566/
img.sootoo.com/user/data/36567/
img.sootoo.com/user/data/36568/
img.sootoo.com/user/data/36569/
img.sootoo.com/user/data/36570/
img.sootoo.com/user/data/36571/
img.sootoo.com/user/data/36572/
img.sootoo.com/user/data/36573/
img.sootoo.com/user/data/36574/
img.sootoo.com/user/data/36575/
img.sootoo.com/user/data/36576/
img.sootoo.com/user/data/36577/
img.sootoo.com/user/data/36578/
img.sootoo.com/user/data/36579/
img.sootoo.com/user/data/36580/
img.sootoo.com/user/data/36581/
img.sootoo.com/user/data/36582/
img.sootoo.com/user/data/36583/
img.sootoo.com/user/data/36584/
img.sootoo.com/user/data/36585/
img.sootoo.com/user/data/36586/
img.sootoo.com/user/data/36587/
img.sootoo.com/user/data/36588/
img.sootoo.com/user/data/36589/
img.sootoo.com/user/data/36590/
img.sootoo.com/user/data/36591/
img.sootoo.com/user/data/36592/
img.sootoo.com/user/data/36593/
img.sootoo.com/user/data/36594/
img.sootoo.com/user/data/36595/
img.sootoo.com/user/data/36596/
img.sootoo.com/user/data/36597/
img.sootoo.com/user/data/36598/
img.sootoo.com/user/data/36599/
img.sootoo.com/user/data/36600/
img.sootoo.com/user/data/36601/
img.sootoo.com/user/data/36602/
img.sootoo.com/user/data/36603/
img.sootoo.com/user/data/36604/
img.sootoo.com/user/data/36605/
img.sootoo.com/user/data/36606/
img.sootoo.com/user/data/36607/
img.sootoo.com/user/data/36608/
img.sootoo.com/user/data/36609/
img.sootoo.com/user/data/36610/
img.sootoo.com/user/data/36611/
img.sootoo.com/user/data/36612/
img.sootoo.com/user/data/36613/
img.sootoo.com/user/data/36614/
img.sootoo.com/user/data/36615/
img.sootoo.com/user/data/36616/
img.sootoo.com/user/data/36617/
img.sootoo.com/user/data/36618/
img.sootoo.com/user/data/36619/
img.sootoo.com/user/data/36620/
img.sootoo.com/user/data/36621/
img.sootoo.com/user/data/36622/
img.sootoo.com/user/data/36623/
img.sootoo.com/user/data/36624/
img.sootoo.com/user/data/36625/
img.sootoo.com/user/data/36626/
img.sootoo.com/user/data/36627/
img.sootoo.com/user/data/36628/
img.sootoo.com/user/data/36629/
img.sootoo.com/user/data/36630/
img.sootoo.com/user/data/36631/
img.sootoo.com/user/data/36632/
img.sootoo.com/user/data/36633/
img.sootoo.com/user/data/36634/
img.sootoo.com/user/data/36635/
img.sootoo.com/user/data/36636/
img.sootoo.com/user/data/36637/
img.sootoo.com/user/data/36638/
img.sootoo.com/user/data/36639/
img.sootoo.com/user/data/36640/
img.sootoo.com/user/data/36641/
img.sootoo.com/user/data/36642/
img.sootoo.com/user/data/36643/
img.sootoo.com/user/data/36644/
img.sootoo.com/user/data/36646/
img.sootoo.com/user/data/36647/
img.sootoo.com/user/data/36648/
img.sootoo.com/user/data/36649/
img.sootoo.com/user/data/36650/
img.sootoo.com/user/data/36651/
img.sootoo.com/user/data/36652/
img.sootoo.com/user/data/36653/
img.sootoo.com/user/data/36654/
img.sootoo.com/user/data/36655/
img.sootoo.com/user/data/36656/
img.sootoo.com/user/data/36657/
img.sootoo.com/user/data/36658/
img.sootoo.com/user/data/36659/
img.sootoo.com/user/data/36660/
img.sootoo.com/user/data/36661/
img.sootoo.com/user/data/36662/
img.sootoo.com/user/data/36663/
img.sootoo.com/user/data/36664/
img.sootoo.com/user/data/36665/
img.sootoo.com/user/data/36666/
img.sootoo.com/user/data/36667/
img.sootoo.com/user/data/36668/
img.sootoo.com/user/data/36669/
img.sootoo.com/user/data/36670/
img.sootoo.com/user/data/36671/
img.sootoo.com/user/data/36672/
img.sootoo.com/user/data/36673/
img.sootoo.com/user/data/36674/
img.sootoo.com/user/data/36675/
img.sootoo.com/user/data/36676/
img.sootoo.com/user/data/36677/
img.sootoo.com/user/data/36678/
img.sootoo.com/user/data/36679/
img.sootoo.com/user/data/36680/
img.sootoo.com/user/data/36681/
img.sootoo.com/user/data/36682/
img.sootoo.com/user/data/36683/
img.sootoo.com/user/data/36684/
img.sootoo.com/user/data/36685/
img.sootoo.com/user/data/36686/
img.sootoo.com/user/data/36687/
img.sootoo.com/user/data/36688/
img.sootoo.com/user/data/36689/
img.sootoo.com/user/data/36690/
img.sootoo.com/user/data/36691/
img.sootoo.com/user/data/36692/
img.sootoo.com/user/data/36694/
img.sootoo.com/user/data/36695/
img.sootoo.com/user/data/36696/
img.sootoo.com/user/data/36697/
img.sootoo.com/user/data/36698/
img.sootoo.com/user/data/36699/
img.sootoo.com/user/data/36700/
img.sootoo.com/user/data/36701/
img.sootoo.com/user/data/36702/
img.sootoo.com/user/data/36703/
img.sootoo.com/user/data/36704/
img.sootoo.com/user/data/36705/
img.sootoo.com/user/data/36706/
img.sootoo.com/user/data/36707/
img.sootoo.com/user/data/36708/
img.sootoo.com/user/data/36709/
img.sootoo.com/user/data/36710/
img.sootoo.com/user/data/36711/
img.sootoo.com/user/data/36712/
img.sootoo.com/user/data/36713/
img.sootoo.com/user/data/36714/
img.sootoo.com/user/data/36715/
img.sootoo.com/user/data/36716/
img.sootoo.com/user/data/36717/
img.sootoo.com/user/data/36718/
img.sootoo.com/user/data/36719/
img.sootoo.com/user/data/36720/
img.sootoo.com/user/data/36721/
img.sootoo.com/user/data/36722/
img.sootoo.com/user/data/36723/
img.sootoo.com/user/data/36724/
img.sootoo.com/user/data/36725/
img.sootoo.com/user/data/36726/
img.sootoo.com/user/data/36727/
img.sootoo.com/user/data/36728/
img.sootoo.com/user/data/36730/
img.sootoo.com/user/data/36731/
img.sootoo.com/user/data/36732/
img.sootoo.com/user/data/36733/
img.sootoo.com/user/data/36734/
img.sootoo.com/user/data/36735/
img.sootoo.com/user/data/36736/
img.sootoo.com/user/data/36737/
img.sootoo.com/user/data/36738/
img.sootoo.com/user/data/36739/
img.sootoo.com/user/data/36740/
img.sootoo.com/user/data/36741/
img.sootoo.com/user/data/36742/
img.sootoo.com/user/data/36743/
img.sootoo.com/user/data/36744/
img.sootoo.com/user/data/36745/
img.sootoo.com/user/data/36746/
img.sootoo.com/user/data/36747/
img.sootoo.com/user/data/36748/
img.sootoo.com/user/data/36749/
img.sootoo.com/user/data/36750/
img.sootoo.com/user/data/36751/
img.sootoo.com/user/data/36752/
img.sootoo.com/user/data/36754/
img.sootoo.com/user/data/36755/
img.sootoo.com/user/data/36756/
img.sootoo.com/user/data/36757/
img.sootoo.com/user/data/36758/
img.sootoo.com/user/data/36759/
img.sootoo.com/user/data/36760/
img.sootoo.com/user/data/36761/
img.sootoo.com/user/data/36762/
img.sootoo.com/user/data/36763/
img.sootoo.com/user/data/36764/ 

郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。