Question

以下查询需要大约3000毫秒才能执行。我无法微调这个查询以获得相当大的性能优势。

declare @EndDate datetime;
declare @FromDate datetime;
set @EndDate = getdate();
set @FromDate = DATEADD(year,-1, @EndDate);

    SELECT [twc].ColumnId, [twc].ColumnName
    FROM [table1] twcs with(nolock)
        INNER JOIN [table2] twc with(nolock) ON [twc].ColumnId = [twcs].ColumnId 
        WHERE [twcs].[ColumnName] = 1 AND [twc].[CreateDate] between @fromdate and @enddate;

Answer 1

这是您的查询：

SELECT twc.ColumnId, twc.ColumnName
FROM table1 twcs with (nolock) INNER JOIN
     table2 twc with (nolock)
     ON twc.ColumnId = twcs.ColumnId 
WHERE twcs.ColumnName = 1 AND twc.CreateDate between @fromdate and @enddate;

我建议使用以下索引，如下所示：

table2(CreateDate, ColumnId)
table2(ColumnId, CreateDate)
table1(ColumnName, ColumnId)
table1(ColumnId, ColumnName)

让优化器选择使用哪个。

Answer 2

使用简单直接的查询，您可能会查看表需要新索引来加速返回而不是脚本优化的问题。

Finetuning SQL查询性能

2 个答案: