如何用NHibernate设置正确的事务隔离模式?

我们已经从sqlite切换到FireBird嵌入式服务器,因为FB 有以下例外:

2010-10-28 15:49:31,242 [56] ERROR NetworkCatcher.Entities.Agent.Server.RunResultManager - Failed to send result to server 32W2K3SP2VM-DEV. NHibernate.Exceptions.GenericADOException: could not update: ExecutionEntry#89_19_32W2K3SP2VM-DEV][SQL: UPDATE Run SET ExecutionId = ?, Source = ?, Destination = ?, ProtocolId = ?, Duration = ?, SampleCount = ?, StartTime = ?, ServerHostName = ?, SamplesSentToServer = ?, SampleInterval = ?, Parameters = ? WHERE Id = ?] ---> FirebirdSql.Data.FirebirdClient.FbException: deadlock
update conflicts with concurrent update
concurrent transaction number is 31632 --->
FirebirdSql.Data.Common.IscException: deadlock
update conflicts with concurrent update
concurrent transaction number is 31632
   at FirebirdSql.Data.Client.Native.FesDatabase.ParseStatusVector(IntPtr[]
statusVector)
   at FirebirdSql.Data.Client.Native.FesStatement.Execute()
   at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteCommand(CommandBehavior
behavior, Boolean returnsSet)
   at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteCommand(CommandBehavior
behavior)
   at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteNonQuery()
.
.
.

FB对此的反应是 你为什么认为是虫子?这是一个定期的更新冲突导致 两个事务同时更新同一记录。是什么 您的事务隔离模式?

这句话曾两次使我困惑,因为我很不愉快 惊奇地发现我可以同时写同样的记录 第二次我不知道我的 事务隔离模式以及如何使用它将写入序列化到 同样的记录。

正在更新的对象映射为:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-
import="true">
  <class name="NetworkCatcher.Entities.Agent.Server.ExecutionManager+ExecutionEntry,NC.Entities.Agent.Server" lazy="false" table="Run" entity-name="ExecutionEntry">
    <id name="Id" column="Id" type="string" >
      <generator class="assigned"/>
    </id>
    <property name="ExecutionId"/>
    <property name="Source"/>
    <property name="Destination"/>
    <property name="ProtocolId" type="string"/>
    <property name="Duration"/>
    <property name="SampleCount"/>
    <property name="StartTime"/>
    <property name="ServerHostName"/>
    <property name="m_samplesSentToServer" column="SamplesSentToServer" type="int" access="field" />
    <property name="SampleInterval"/>
    <property name="Parameters" type="binary"/>
  </class>
</hibernate-mapping>

我相信外面有个好心人,他知道答案 我的问题。请,请,请分享你的智慧。。。

谢谢。