有两个表A,B
A里有字段(KEY1,KEY2,A1,A2,A3,A4,A5)
B里有字段(KEY1,KEY2,B1,B2,B3,B4,B5)A里有索引 IND1(KEY1,KEY2)
B里有索引 IND1(KEY1,KEY2)A表里有100万条记录
B表里有300万条记录我现在用这条语句为什么执行起来要6分钟多select A.KEY1,A.KEY2,A.A1,A.A2,B.B1,B.B2,B.B3 from A left join B on A.KEY1=B.KEY1 and A.KEY2=B.KEY2怎么优化也优化不了,郁闷西,分不够再加
A里有字段(KEY1,KEY2,A1,A2,A3,A4,A5)
B里有字段(KEY1,KEY2,B1,B2,B3,B4,B5)A里有索引 IND1(KEY1,KEY2)
B里有索引 IND1(KEY1,KEY2)A表里有100万条记录
B表里有300万条记录我现在用这条语句为什么执行起来要6分钟多select A.KEY1,A.KEY2,A.A1,A.A2,B.B1,B.B2,B.B3 from A left join B on A.KEY1=B.KEY1 and A.KEY2=B.KEY2怎么优化也优化不了,郁闷西,分不够再加
Dim rs As ADODB.Recordset
Dim cn As ADODB.Connection
Set cn = New ADODB.Connection
cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=False" & _
";Data Source=你的数据库.mdb"
Set rs = New ADODB.Recordset
With rs
.CursorLocation = adUseClient
.Open "select A.KEY1,A.KEY2,A.A1,A.A2,B.B1,B.B2,B.B3 from A left join B on A.KEY1=B.KEY1 and A.KEY2=B.KEY2 ", cn, adOpenKeyset, adLockOptimistic
.PageSize = 10
iPageCount = .PageCount
iRecords = .PageSize
End With
select A.KEY1,A.KEY2,A.A1,A.A2,B.B1,B.B2,B.B3 from A left join B on A.KEY1=B.KEY1 and A.KEY2=B.KEY2
group by A.A1,A.A2
我改了下建了一个新的索引,KEY1,KEY2,B1,B2,B3 ,可是再分析下还是用老的索引,郁闷啊