MySQL Data high paging efficiency

My code is a large amount of data to improve paging efficiency test code
--Improve paging efficiency: to achieve paging only read display data, you need to create a database in the database "testforpaging"
Use testforpaging
Go
--Create TABLE Somedata
CREATE table Somedata
(
ID int primary KEY,
name varchar () NULL,
Description text
)
Go
--insert data
INSERT INTO somedata values (1, ' num1 ', ' 1th ')
Go
insert INTO somedata values (2, ' num2 ', ' 2nd ')
Go
Inserts into the Somedata values (3, ' num3 ', ' 3rd ')
Go
inserts into Somedata values (4, ' num4 ', ' 4th ')
Go
INSERT into Somedata values (5, ' NUM5 ', ' 5th ')
Go
--Total number of data entries
Select COUNT (*) from Somedata
Go
- Add a data level to each record
Select Name,description,row_number () over (order by id DESC) as datalevel from Somedata
Go

--View the data entry between the specified data levels
Select Datalevel,name,description from
(select Name,description,row_number () over (order by id DESC) as datalevel from Somedata)
As Datawithleverl where datalevel between 2 and 4
Go
--A stored procedure that enables you to view data entries between specified data levels
CREATE PROCEDURE Getdatapaged
(
@startRowIndex int,
@maximumRows int,
@sort varchar
)
As
--Ensure that the sort is specified
If Len (@sort) =0
Set @sort = ' id '
--Query with parameters
Select Datalevel,name,description from
(select Name,description,row_number () over (order by @sort Desc) as Datalevel from Somedata) As Datawithleverl
WHERE datalevel > (@startRowIndex *10) and Datalevel <= (@startRowIndex *10 + @maximumRows)
Go