CODEWITHSUNDEEP
mysqlasp-classicadorecordset
user1119112
user1119112

Reputation: 827

How to improve perfomance of recordset handling

I've written a web application in ASP which reads 3600 rows from a MySQL database (v5.1.63) and outputs the data in an HTML table. I'm using a recordset to get the data and pagesize/cursorlocation to let the user step forward/backward between the pages. The database contains some 200.000 rows right now but is continuously growing.

The page takes longer and longer to load (approx. 15-20 seconds now) and I would like to optimize it if possible.

I would be very interested in getting tips on how to improve the performance.

Here is the database structure:

#   Col   Type          Collation       Attributes  Null    Default
1   ID    int(11)                         No       None     AUTO_INCREMENT
2   mean  varchar(5)    utf8_general_ci   No       None 
3   max   varchar(5)    utf8_general_ci   No       None 
4   min   varchar(5)    utf8_general_ci   No       None 
5   dt    varchar(20)   utf8_general_ci   No       None 
6   dir   varchar(2)    utf8_general_ci   No       None 
7   log   text          utf8_general_ci   No       None

Here is the code I'm using:

' Opening the db
Set oConn = Server.CreateObject("ADODB.Connection")
Set oRS = Server.CreateObject("ADODB.Recordset")
oConn.ConnectionString =
"DRIVER={MySQL};SERVER=<server>;DATABASE=<database>;UID=<uid>;PWD=<pwd>;"
oConn.Open

' Retrieve 3600 records
sSQL = "SELECT * FROM mytable ORDER BY id DESC"
oRS.CursorLocation = adUseServer
oRS.PageSize = 6*600
oRS.Open sSQL, oConn, adOpenForwardOnly, adLockReadOnly
nPageCount = oRS.PageCount

...code to set the page selected by the user (nPage)

oRS.AbsolutePage = nPage

Do While Not (oRS.EOF Or oRS.AbsolutePage <> nPage)
    ...
    Response.Write("<td>" & oRS("dt") & "</td>")
    Response.Write("<td>" & oRS("mean") & "</td>")
    Response.Write("<td>" & oRS("min") & "</td>")
    Response.Write("<td>" & oRS("max") & "</td>")
    ...
    oRS.MoveNext
Loop
oRS.Close

Upvotes: 1

Views: 334

Answers (1)

HeavenCore
HeavenCore

Reputation: 7683

If you're using MySQL as the RDMS - it would be far more efficient if you performed the paging using mySqls LIMIT clause:

i.e. to get 10 items per page for a given querystring page number:

ItemsPerPage    = 10
PageNumber      = request.querystring("Page")

if PageNumber = "" then 
    PageNumber = 0
end if

Limit           = PageNumber * ItemsPerPage
Query           = "SELECT * FROM mytable ORDER BY id DESC LIMIT " & Limit & ", " & ItemsPerPage

Upvotes: 2

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