我有一个查询,如下所示,它有一个列上的聚集索引,[Generated_red_ident]。在下面提到的查询的列必须是非聚集索引?索引策略在sql server 2000中查询与group by子句
我可以理解Episode_Number是非聚簇索引的好候选者。 列methd和start_date1怎么样?
另外,我是否也必须在group by子句中的所有列上创建非聚集索引?
请在查询所有coloumn sugest
SELECT [ID],
[Number],
[Age],
[Start_Date],
[Pr],
[Mthd],
[Identifier],
CASE
WHEN [methd] IN (21, 22, 23, 24,28) THEN 'er'
END AS 'ner',
CASE
WHEN Datepart(dw, [Start_Date1]) in (1,7) THEN 'Weekend'
END AS 'weekday'
FROM [PPL_Data]
WHERE [Episode_Number] = 1
GROUP BY [ID],
[Number],
[Age],
[Start_Date],
[Pr],
[Mthd],
[Identifier]