性能调优小 T-SQL IF ELSE 状态，运行数千次

Question

>我试图从这个查询中挤出一些性能，任何帮助将不胜感激，我唯一能做的就是在第二个语句上删除顺序，因为它是按主键排序的

--SET STATISTICS TIME ON
DECLARE             
        @MasterAdGroupId Int = 3469476,
        @IncludeDeleted Bit = 1,
        @Deleted Bit = 0,
        @IncludeDirty Bit= 0,
        @Dirty Bit =1,
        @IncludeDupes Bit=0,
        @OrderByText Bit= 1,
        @UseInDisplayNetworkOnly Bit=0
BEGIN
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED 
IF @OrderByText=1 
BEGIN
    SELECT MasterKeywordId, Text, URL, MasterAdGroupId, mk.KeywordTemplateId, Dirty, mk.Deleted, Negative, Duplicate  
      FROM admanMasterKeyword_tbl mk
INNER JOIN admanKeywordTemplate_tbl kt on kt.KeywordTemplateId = mk.KeywordTemplateId
     WHERE MasterAdGroupId = @MasterAdGroupId 
       AND mk.Deleted = CASE WHEN @IncludeDeleted=0 THEN @Deleted ELSE mk.Deleted END
       AND Dirty = CASE WHEN @IncludeDirty=0 THEN @Dirty ELSE Dirty END
       AND Duplicate = CASE WHEN @IncludeDupes=1 THEN Duplicate ELSE 0 END
       AND UseInDisplayNetwork = CASE WHEN @UseInDisplayNetworkOnly=1 THEN 1 ELSE UseInDisplayNetwork END
  ORDER BY Text 
END
ELSE
BEGIN
    SELECT MasterKeywordId, Text, URL, MasterAdGroupId, mk.KeywordTemplateId, Dirty, mk.Deleted, Negative, Duplicate  
      FROM admanMasterKeyword_tbl mk
INNER JOIN admanKeywordTemplate_tbl kt on kt.KeywordTemplateId = mk.KeywordTemplateId
     WHERE MasterAdGroupId = @MasterAdGroupId 
       AND mk.Deleted = CASE WHEN @IncludeDeleted=0 THEN @Deleted ELSE mk.Deleted END
       AND Dirty = CASE WHEN @IncludeDirty=0 THEN @Dirty ELSE Dirty END
       AND Duplicate = CASE WHEN @IncludeDupes=1 THEN Duplicate ELSE 0 END
       AND UseInDisplayNetwork = CASE WHEN @UseInDisplayNetworkOnly=1 THEN 1 ELSE UseInDisplayNetwork END
  ORDER BY MasterKeywordId 
END
END

Answer 1

这不会改变任何性能，但是如果您在两个查询中更改的只是它们的排序方式（我看不到任何差异），则可以将CASE语句放在ORDER BY中，而不必重复自己或根本不执行IF语句：

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED 
    SELECT MasterKeywordId, Text, URL, MasterAdGroupId, mk.KeywordTemplateId, Dirty, mk.Deleted, Negative, Duplicate  
      FROM admanMasterKeyword_tbl mk
INNER JOIN admanKeywordTemplate_tbl kt on kt.KeywordTemplateId = mk.KeywordTemplateId
     WHERE MasterAdGroupId = @MasterAdGroupId 
       AND mk.Deleted = CASE WHEN @IncludeDeleted=0 THEN @Deleted ELSE mk.Deleted END
       AND Dirty = CASE WHEN @IncludeDirty=0 THEN @Dirty ELSE Dirty END
       AND Duplicate = CASE WHEN @IncludeDupes=1 THEN Duplicate ELSE 0 END
       AND UseInDisplayNetwork = CASE WHEN @UseInDisplayNetworkOnly=1 THEN 1 ELSE UseInDisplayNetwork END
  ORDER BY (CASE WHEN @OrderByText = 1 THEN Text ELSE MasterKeywordId END) 

此查询的查询计划是什么样的？您可以在任何地方创建索引？