C# “获取异常”;重复交易标识符“;使用Transaction.Current.DependentClone时
我正在创建一种机制,以便将大量新记录批量插入(导入)到ORACLE数据库中。我正在使用多线程和依赖事务: 创建线程:C# “获取异常”;重复交易标识符“;使用Transaction.Current.DependentClone时,c#,multithreading,oracle,transactions,.net-3.5,C#,Multithreading,Oracle,Transactions,.net 3.5,我正在创建一种机制,以便将大量新记录批量插入(导入)到ORACLE数据库中。我正在使用多线程和依赖事务: 创建线程: const int ThreadCount = 4; using (TransactionScope transaction = new TransactionScope()) { List<Thread> threads = new List<Thread>(threadCount); for (int i = 0; i < Thr
const int ThreadCount = 4;
using (TransactionScope transaction = new TransactionScope())
{
List<Thread> threads = new List<Thread>(threadCount);
for (int i = 0; i < ThreadCount; i++)
{
Thread thread = new Thread(WorkerThread);
thread.Start(Transaction.Current.DependentClone(DependentCloneOption.BlockCommitUntilComplete));
threads.Add(thread);
}
threads.ForEach(thread => thread.Join());
transaction.Complete();
}
在此操作过程中,我得到一个类型为System.Data.OracleClient.OracleException
的异常,消息为ORA-24757:duplicate transaction identifier
我做错了什么?我是否以错误的方式实现依赖事务?它与Oracle不兼容吗?如果是,是否存在工作区?我不知道为什么会出现这种异常,但解决方法可能是:
const int ThreadCount = 4;
using (var connection = new OracleConnection(MyConnectionstring))
{
connection.Open();
using (var transaction = connection.BeginTransaction())
{
List<Thread> threads = new List<Thread>(ThreadCount);
for (int i = 0; i < ThreadCount; i++)
{
Thread thread = new Thread(WorkerThread);
thread.Start(transaction);
threads.Add(thread);
}
threads.ForEach(thread => thread.Join());
transaction.Commit();
}
}
虽然我很欣赏这一努力,但它并没有真正的帮助。由于一个连接不能由多个线程共享,因此该连接将在执行其(非)查询时“锁定”该连接。这导致了一个比单线程环境更慢的解决方案……我更仔细地考虑了您的解决方案。当“准备”部分(如导入、收集数据等)变得越来越大时,它只会越来越快。不是螺纹插入件会加快速度,而是“准备”部分可以在多个螺纹上分离的事实。记录“准备”(并行)后,可以将其写入数据库,在您的情况下,该数据库将成为锁定插入操作的队列。
const int ThreadCount = 4;
using (var connection = new OracleConnection(MyConnectionstring))
{
connection.Open();
using (var transaction = connection.BeginTransaction())
{
List<Thread> threads = new List<Thread>(ThreadCount);
for (int i = 0; i < ThreadCount; i++)
{
Thread thread = new Thread(WorkerThread);
thread.Start(transaction);
threads.Add(thread);
}
threads.ForEach(thread => thread.Join());
transaction.Commit();
}
}
private void WorkerThread(object transaction)
{
OracleTransaction trans = (OracleTransaction) transaction;
using (OracleCommand command = trans.Connection.CreateCommand())
{
command.CommandText = "INSERT INTO mytable (x) values (1) ";
command.ExecuteNonQuery();
}
}