Is there any performance issue using Row_Number to implement table paging in Sql Server 2008?
- by majkinetor
I want to implement table paging using this method:
SET @PageNum = 2;
SET @PageSize = 10;
WITH OrdersRN AS
(
SELECT ROW_NUMBER() OVER(ORDER BY OrderDate, OrderID) AS RowNum
,*
FROM dbo.Orders
)
SELECT *
FROM OrdersRN
WHERE RowNum BETWEEN (@PageNum - 1) * @PageSize + 1
AND @PageNum * @PageSize
ORDER BY OrderDate ,OrderID;
Is there anything I should be aware of ?
Table has millions of records.
Thx.
EDIT:
After using suggested MAXROWS method for some time (which works really really fast) I had to switch back to ROW_NUMBER method because of its greater flexibility. I am also very happy about its speed so far (I am working with View having more then 1M records with 10 columns). To use any kind of query I use following modification:
PROCEDURE [dbo].[PageSelect]
(
@Sql nvarchar(512),
@OrderBy nvarchar(128) = 'Id',
@PageNum int = 1,
@PageSize int = 0
)
AS
BEGIN
SET NOCOUNT ON
Declare @tsql as nvarchar(1024)
Declare @i int, @j int
if (@PageSize <= 0) OR (@PageSize > 10000)
SET @PageSize = 10000 -- never return more then 10K records
SET @i = (@PageNum - 1) * @PageSize + 1
SET @j = @PageNum * @PageSize
SET @tsql =
'WITH MyTableOrViewRN AS
(
SELECT ROW_NUMBER() OVER(ORDER BY ' + @OrderBy + ') AS RowNum
,*
FROM MyTableOrView
WHERE ' + @Sql + '
)
SELECT *
FROM MyTableOrViewRN
WHERE RowNum BETWEEN ' + CAST(@i as varchar) + ' AND ' + cast(@j as varchar)
exec(@tsql)
END
If you use this procedure make sure u prevented sql injection.
