isolation-level

问题 I think the above isolation levels are so alike. Could someone please describe with some nice examples what the main difference is ? 回答1: Read committed is an isolation level that guarantees that any data read was committed at the moment is read. It simply restricts the reader from seeing any intermediate, uncommitted, 'dirty' read. IT makes no promise whatsoever that if the transaction re-issues the read, will find the Same data, data is free to change after it was read. Repeatable read is a

问题 In plain English, what are the disadvantages and advantages of using SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED in a query for .NET applications and reporting services applications? 回答1: This isolation level allows dirty reads. One transaction may see uncommitted changes made by some other transaction. To maintain the highest level of isolation, a DBMS usually acquires locks on data, which may result in a loss of concurrency and a high locking overhead. This isolation level relaxes this