摘要： checkpointdbcc freeproccachedbcc dropcleanbuffers1. SELECT count(*) FROM Users WHERE Users.UserName like '%ljh%'2. SELECT 1 FROM Users WHERE Users.UserName like '%ljh%'3. SELECT Top 1 1 FROM Users WHERE Users.UserName LIKE '%ljh%'经测试第3种方法性能最佳，测试数据量为6百万多条。 阅读全文