我用ASP编写了一个web应用程序,它从MySQL数据库(v5.1.63)读取3600行,并将数据输出到HTML表中。我使用记录集来获取数据,使用pagesize/cursorlocation让用户在页面之间前进/后退。该数据库目前包含约200.000行,但仍在不断增长。
页面加载时间越来越长(现在大约需要15-20秒),如果可能的话,我想对它进行优化。
我很想知道如何提高性能的技巧。
以下是数据库结构:

#   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

最佳答案

如果使用MySQL作为RDMS,那么如果使用mySqlsLIMIT子句执行分页,效率会高得多:
即,对于给定的查询字符串页码,每页获取10个项目:

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

10-06 02:07