Microsoft SQL Server 2005 中的默认隔离级别
SQL Server 2005 中的默认隔离级别是什么?您希望在什么情况下更改它?关于默认隔离级别的解释很少,我们将不胜感激。
感谢期待
What is the default isolation level in SQL Server 2005 and in which scenario would you want to change it ? And little explanation about the default isolation level would be appreciated.
Thanks in anticipation
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默认值 = READ COMMITTED
您不需要经常更改它。有些人建议“始终使用 READ UNCOMMITTED”,但这很危险。
至于为什么,我建议维基百科,但总的来说有可能发生的 3 种数据读取问题:
当您以降低并发性为代价提高隔离性(至可串行化)时,这些问题中的每一个都会被删除。
默认级别可以防止“脏读”,坦率地说已经足够好了。
Default = READ COMMITTED
You don't need to change it often. Some folk recommend "always use READ UNCOMMITTED" but this is dangerous.
As to why, I'd suggest Wikipedia but in summary there are 3 data read issues that can occur:
Each of these is removed as you increase isolation (to SERIALIZABLE) at the cost of reduced concurrency.
The default level prevents "Dirty reads" and frankly is good enough.