优化你的DiscuzNT3.0，让它跑起来（2）发帖回帖篇

注：本文仅针对 DiscuzNT3.0, sqlserver 2000版本，其他版本请勿对号入座.

上次对DiscuzNT的看帖做了性能优化，这次主要针对发帖和回帖做下优化，本文还是以优化数据库为主，C#的优化以后有时间另外记录。

看帖，发帖，回帖 都是一个论坛的基本操作，如果性能不好导致这些操作变慢，论坛的效果可想而知了，那我们来看看DiscuzNT发帖和回帖都有些什么操作，性能如何。

做事情总要有个先后，我给这次的优化工作也做了个步骤：（有图有真相）

1）看代码，查到发帖回帖调用的存储过程；

发帖调用了两个过程，代码如下：

  public   int  CreateTopic(TopicInfo topicInfo)
{
    DbParameter[] parms  =  {
    DbHelper.MakeInParam( " @fid " , (DbType)SqlDbType.SmallInt,  2 , topicInfo.Fid), 
    DbHelper.MakeInParam( " @iconid " , (DbType)SqlDbType.SmallInt,  2 , topicInfo.Iconid), 
    DbHelper.MakeInParam( " @title " , (DbType)SqlDbType.NChar,  60 , topicInfo.Title), 
    DbHelper.MakeInParam( " @typeid " , (DbType)SqlDbType.SmallInt,  2 , topicInfo.Typeid), 
    DbHelper.MakeInParam( " @readperm " , (DbType)SqlDbType.Int,  4 , topicInfo.Readperm), 
    DbHelper.MakeInParam( " @price " , (DbType)SqlDbType.SmallInt,  2 , topicInfo.Price), 
    DbHelper.MakeInParam( " @poster " , (DbType)SqlDbType.NChar,  15 , topicInfo.Poster), 
    DbHelper.MakeInParam( " @posterid " , (DbType)SqlDbType.Int,  4 , topicInfo.Posterid), 
    DbHelper.MakeInParam( " @postdatetime " , (DbType)SqlDbType.SmallDateTime, 4 , DateTime.Parse(topicInfo.Postdatetime)), 
    DbHelper.MakeInParam( " @lastpost " , (DbType)SqlDbType.VarChar,  0 , topicInfo.Lastpost), 
    DbHelper.MakeInParam( " @lastpostid " , (DbType)SqlDbType.Int,  4 , topicInfo.Lastpostid),
    DbHelper.MakeInParam( " @lastposter " , (DbType)SqlDbType.NChar,  15 , topicInfo.Lastposter), 
    DbHelper.MakeInParam( " @views " , (DbType)SqlDbType.Int,  4 , topicInfo.Views), 
    DbHelper.MakeInParam( " @replies " , (DbType)SqlDbType.Int,  4 , topicInfo.Replies), 
    DbHelper.MakeInParam( " @displayorder " , (DbType)SqlDbType.Int,  4 , topicInfo.Displayorder), 
    DbHelper.MakeInParam( " @highlight " , (DbType)SqlDbType.VarChar,  500 , topicInfo.Highlight), 
    DbHelper.MakeInParam( " @digest " , (DbType)SqlDbType.Int,  4 , topicInfo.Digest), 
    DbHelper.MakeInParam( " @rate " , (DbType)SqlDbType.Int,  4 , topicInfo.Rate), 
    DbHelper.MakeInParam( " @hide " , (DbType)SqlDbType.Int,  4 , topicInfo.Hide), 
    DbHelper.MakeInParam( " @attachment " , (DbType)SqlDbType.Int,  4 , topicInfo.Attachment), 
    DbHelper.MakeInParam( " @moderated " , (DbType)SqlDbType.Int,  4 , topicInfo.Moderated), 
    DbHelper.MakeInParam( " @closed " , (DbType)SqlDbType.Int,  4 , topicInfo.Closed),
    DbHelper.MakeInParam( " @magic " , (DbType)SqlDbType.Int,  4 , topicInfo.Magic),
    DbHelper.MakeInParam( " @special " , (DbType)SqlDbType.TinyInt,  1 , topicInfo.Special),
    DbHelper.MakeInParam( " @attention " , (DbType)SqlDbType.Int,  4 , topicInfo.Attention)
        };
     return  TypeConverter.ObjectToInt(DbHelper.ExecuteDataset(CommandType.StoredProcedure,
     string .Format( " {0}createtopic " , BaseConfigs.GetTablePrefix),
    parms).Tables[ 0 ].Rows[ 0 ][ 0 ],  - 1 );

}  

 

  /// <summary>

///  创建帖子
///   </summary>
///   <param name="postinfo"> 帖子信息类 </param>
///   <returns> 返回帖子id </returns>
public   int  CreatePost(PostInfo postInfo,  string  postTableId)
{
    DbParameter[] parms  =  {
    DbHelper.MakeInParam( " @fid " ,(DbType)SqlDbType.SmallInt, 2 ,postInfo.Fid),
    DbHelper.MakeInParam( " @tid " ,(DbType)SqlDbType.Int, 4 ,postInfo.Tid),
    DbHelper.MakeInParam( " @parentid " ,(DbType)SqlDbType.Int, 4 ,postInfo.Parentid),
    DbHelper.MakeInParam( " @layer " ,(DbType)SqlDbType.Int, 4 ,postInfo.Layer),
    DbHelper.MakeInParam( " @poster " ,(DbType)SqlDbType.VarChar, 15 ,postInfo.Poster),
    DbHelper.MakeInParam( " @posterid " ,(DbType)SqlDbType.Int, 4 ,postInfo.Posterid),
    DbHelper.MakeInParam( " @title " ,(DbType)SqlDbType.NVarChar, 60 ,postInfo.Title),
    DbHelper.MakeInParam( " @topictitle " ,(DbType)SqlDbType.NVarChar, 60 ,postInfo.Topictitle),
    DbHelper.MakeInParam( " @postdatetime " ,(DbType)SqlDbType.SmallDateTime, 4 , DateTime.Parse(postInfo.Postdatetime)),
    DbHelper.MakeInParam( " @message " ,(DbType)SqlDbType.NText, 0 ,postInfo.Message),
    DbHelper.MakeInParam( " @ip " ,(DbType)SqlDbType.VarChar, 15 ,postInfo.Ip),
    DbHelper.MakeInParam( " @lastedit " ,(DbType)SqlDbType.NVarChar, 50 ,postInfo.Lastedit),
    DbHelper.MakeInParam( " @invisible " ,(DbType)SqlDbType.Int, 4 ,postInfo.Invisible),
    DbHelper.MakeInParam( " @usesig " ,(DbType)SqlDbType.Int, 4 ,postInfo.Usesig),
    DbHelper.MakeInParam( " @htmlon " ,(DbType)SqlDbType.Int, 4 ,postInfo.Htmlon),
    DbHelper.MakeInParam( " @smileyoff " ,(DbType)SqlDbType.Int, 4 ,postInfo.Smileyoff),
    DbHelper.MakeInParam( " @bbcodeoff " ,(DbType)SqlDbType.Int, 4 ,postInfo.Bbcodeoff),
    DbHelper.MakeInParam( " @parseurloff " ,(DbType)SqlDbType.Int, 4 ,postInfo.Parseurloff),
    DbHelper.MakeInParam( " @attachment " ,(DbType)SqlDbType.Int, 4 ,postInfo.Attachment),
    DbHelper.MakeInParam( " @rate " ,(DbType)SqlDbType.SmallInt, 2 ,postInfo.Rate),
    DbHelper.MakeInParam( " @ratetimes " ,(DbType)SqlDbType.Int, 4 ,postInfo.Ratetimes)
       };
     return  TypeConverter.ObjectToInt(DbHelper.ExecuteScalar(CommandType.StoredProcedure,
     string .Format( " {0}createpost{1} " , BaseConfigs.GetTablePrefix, postTableId),
    parms),  - 1 );
} 

 

有两个主要方法，1个是CreateTopic(),对应调用dnt_createtopic存储过程，这个是把主贴的基本信息保存到dnt_topics表，其中不包含帖子内容；

1个是CreatePost()对应调用dnt_createposts{0},{0}是分表名称，是把帖子的所有信息保存到dnt_posts{0}表，此表帖子的详细信息（包括回复也在此表）；

论坛展示帖子列表的时候查询的是dnt_topics表的信息，帖子里面展示各楼层信息的时候查询的是dnt_posts{0}表。

 

2）发一个帖或者回复一个帖子，看看存储过程的性能 ； 

我们用profiler跟踪一下这两个过程的性能如何,看图: 

 

从上图看到 dnt_createposts3这个过程的reads比较高,我们看看它是怎么写的，有没有优化的可能。

 

3）查看存储过程的sql写法， 如果发现问题，指出问题； 

dnt_createposts3这个过程的脚本如下：

ALTER        PROCEDURE  dnt_createpost3
@fid   int ,
@tid   int ,
@parentid   int ,
@layer   int ,
@poster   varchar ( 20 ),
@posterid   int ,
@title   nvarchar ( 60 ),
@topictitle   nvarchar ( 60 ),
@postdatetime   char ( 20 ),
@message   ntext ,
@ip   varchar ( 15 ),
@lastedit   varchar ( 50 ),
@invisible   int ,
@usesig   int ,
@htmlon   int ,
@smileyoff   int ,
@bbcodeoff   int ,
@parseurloff   int ,
@attachment   int ,
@rate   int ,
@ratetimes   int

AS

DEClARE   @postid   int

DELETE   FROM   [ dnt_postid ]   WHERE   DATEDIFF (n, postdatetime,  GETDATE ())  > 5

INSERT   INTO   [ dnt_postid ]  ( [ postdatetime ] )  VALUES ( GETDATE ())

SELECT   @postid = SCOPE_IDENTITY ()

INSERT   INTO   [ dnt_posts3 ] ( [ pid ] ,  [ fid ] ,  [ tid ] ,  [ parentid ] ,  [ layer ] ,  [ poster ] ,
     [ posterid ] ,  [ title ] ,  [ postdatetime ] ,  [ message ] ,  [ ip ] ,  [ lastedit ] , 
     [ invisible ] ,  [ usesig ] ,  [ htmlon ] ,  [ smileyoff ] ,  [ bbcodeoff ] ,  [ parseurloff ] ,
     [ attachment ] ,  [ rate ] ,  [ ratetimes ] ) 
     VALUES ( @postid ,  @fid ,  @tid ,  @parentid ,  @layer ,  @poster ,  @posterid ,  @title ,
     @postdatetime ,  @message ,  @ip ,  @lastedit ,  @invisible ,  @usesig ,  @htmlon ,  @smileyoff ,
     @bbcodeoff ,  @parseurloff ,  @attachment ,  @rate ,  @ratetimes )

IF   @parentid = 0
BEGIN
     UPDATE   [ dnt_posts3 ]   SET   [ parentid ] = @postid   WHERE   [ pid ] = @postid
END

IF   @@ERROR = 0
BEGIN
     IF    @invisible   =   0
     BEGIN
         UPDATE   [ dnt_statistics ]   SET   [ totalpost ] = [ totalpost ]   +   1

         DECLARE   @fidlist   AS   VARCHAR ( 1000 )
         DECLARE   @strsql   AS   VARCHAR ( 4000 )
            
         SET   @fidlist   =   '' ;
            
         SELECT   @fidlist   =   ISNULL ( [ parentidlist ] , '' )  FROM   [ dnt_forums ]   WHERE   [ fid ]   =   @fid

         IF   RTRIM ( @fidlist ) <> ''
         BEGIN
             SET   @fidlist   =   RTRIM ( @fidlist )  +   ' , '   +   CAST ( @fid   AS   VARCHAR ( 10 ))
         END
         ELSE
         BEGIN
             SET   @fidlist   =   CAST ( @fid   AS   VARCHAR ( 10 ))
         END
            
         --  性能隐患，此sql语句进行了列运算
         UPDATE   [ dnt_forums ]   SET       [ posts ] = [ posts ]   +   1 , 
             [ todayposts ] = CASE  
             WHEN   DATEDIFF ( day ,  [ lastpost ] ,  GETDATE ()) = 0  
             THEN   [ todayposts ] * 1   +   1  
             ELSE   1  
             END ,
             [ lasttid ] = @tid ,    
             [ lasttitle ] = @topictitle ,
             [ lastpost ] = @postdatetime ,
             [ lastposter ] = @poster ,
             [ lastposterid ] = @posterid                              
             WHERE  ( CHARINDEX ( ' , '   +   RTRIM ( [ fid ] )  +   ' , ' ,  ' , '
             +  ( SELECT   @fidlist   AS   [ fid ] )  +   ' , ' )  >   0 ) 
            
            
         UPDATE   [ dnt_users ]   SET
                 [ lastpost ]   =   @postdatetime ,
                 [ lastpostid ]   =   @postid ,
                 [ lastposttitle ]   =   @title ,
                 [ posts ]   =   [ posts ]   +   1 ,
                 [ lastactivity ]   =   GETDATE ()
             WHERE   [ uid ]   =   @posterid
        
        
         IF   @layer <= 0
         BEGIN
             UPDATE   [ dnt_topics ]   SET   [ replies ] = 0 , [ lastposter ] = @poster ,
                 [ lastpost ] = @postdatetime , [ lastposterid ] = @posterid  
                 WHERE   [ tid ] = @tid
         END
         ELSE
         BEGIN
             UPDATE   [ dnt_topics ]   SET   [ replies ] = [ replies ]   +   1 , [ lastposter ] = @poster ,
                 [ lastpost ] = @postdatetime , [ lastposterid ] = @posterid
                 WHERE   [ tid ] = @tid
         END
     END

     UPDATE   [ dnt_topics ]   SET   [ lastpostid ] = @postid   WHERE   [ tid ] = @tid

     IF   @posterid   <>   - 1
     BEGIN
         INSERT   [ dnt_myposts ] ( [ uid ] ,  [ tid ] ,  [ pid ] ,  [ dateline ] ) 
             VALUES ( @posterid ,  @tid ,  @postid ,  @postdatetime )
     END
    
END
    
SELECT   @postid   AS postid

GO 

 这个过程比较长，不过存在性能隐患的脚本上面已经注明，就是update forums 这句，dnt_forums 数据量越大（我们现在有3000个论坛）, 更新这个表所花的时间越多，因为它进行了列运算 WHERE (CHARINDEX(',' + RTRIM([fid]) + ',', ',' + (SELECT @fidlist AS [fid]) + ',') > 0) ，用不到索引。

 

4）优化，测试优化的结果。

 

优化的方法有多种，下面我给出一种优化的方案，使update dnt_forums 这个操作用到索引，优化后的过程如下：

ALTER                PROCEDURE  dnt_createpost3
@fid   int ,
@tid   int ,
@parentid   int ,
@layer   int ,
@poster   varchar ( 20 ),
@posterid   int ,
@title   nvarchar ( 60 ),
@topictitle   nvarchar ( 60 ),
@postdatetime   char ( 20 ),
@message   ntext ,
@ip   varchar ( 15 ),
@lastedit   varchar ( 50 ),
@invisible   int ,
@usesig   int ,
@htmlon   int ,
@smileyoff   int ,
@bbcodeoff   int ,
@parseurloff   int ,
@attachment   int ,
@rate   int ,
@ratetimes   int

AS


declare   @sql   nvarchar ( 4000 )

DEClARE   @postid   int

DELETE   FROM   [ dnt_postid ]   WHERE   DATEDIFF (n, postdatetime,  GETDATE ())  > 5

INSERT   INTO   [ dnt_postid ]  ( [ postdatetime ] )  VALUES ( GETDATE ())

SELECT   @postid = SCOPE_IDENTITY ()

SELECT   @postid   AS  postid


INSERT   INTO   [ dnt_posts3 ] ( [ pid ] ,  [ fid ] ,  [ tid ] ,  [ parentid ] ,  [ layer ] ,  [ poster ] ,
     [ posterid ] ,  [ title ] ,  [ postdatetime ] ,  [ message ] , 
     [ ip ] ,  [ lastedit ] ,  [ invisible ] ,  [ usesig ] ,  [ htmlon ] , 
     [ smileyoff ] ,  [ bbcodeoff ] ,  [ parseurloff ] ,  [ attachment ] ,  [ rate ] ,  [ ratetimes ] )
     VALUES ( @postid ,  @fid ,  @tid ,  @parentid ,  @layer ,  @poster ,  @posterid ,  @title , 
     @postdatetime ,  @message ,  @ip ,  @lastedit ,  @invisible ,
     @usesig ,  @htmlon ,  @smileyoff ,  @bbcodeoff ,  @parseurloff ,  @attachment , 
     @rate ,  @ratetimes )

IF   @parentid = 0
BEGIN
     UPDATE   [ dnt_posts3 ]   SET   [ parentid ] = @postid   WHERE   [ pid ] = @postid
END

IF   @@ERROR = 0
BEGIN
     IF    @invisible   =   0
     BEGIN
         UPDATE   [ dnt_statistics ]   SET   [ totalpost ] = [ totalpost ]   +   1

         DECLARE   @fidlist   AS   VARCHAR ( 1000 )
         DECLARE   @strsql   AS   VARCHAR ( 4000 )

         SET   @fidlist   =   '' ;

         SELECT   @fidlist   =   ISNULL ( [ parentidlist ] , '' ) 
             FROM   [ dnt_forums ]   WHERE   [ fid ]   =   @fid

         IF   RTRIM ( @fidlist ) <> ''
         BEGIN
             SET   @fidlist   =   RTRIM ( @fidlist )  +   ' , '   +   CAST ( @fid   AS   VARCHAR ( 10 ))
         END
         ELSE
         BEGIN
             SET   @fidlist   =   CAST ( @fid   AS   VARCHAR ( 10 ))
         END

         --  此处为优化后的sql语句，用动态sql语句，避免进行列运算，使sql用到索引
         set   @sql   =  
' UPDATE [dnt_forums] SET
    [posts]=[posts] + 1,
    [todayposts]=CASE
    WHEN DATEDIFF(day, [lastpost], GETDATE())=0 THEN [todayposts]*1 + 1
    ELSE 1
    END,
    [lasttid]=@tid,
    [lasttitle]=@topictitle,
    [lastpost]=@postdatetime,
    [lastposter]=@poster,
    [lastposterid]=@posterid
    WHERE [fid] in ( '   +   @fidlist   +   ' ) '

         exec  sp_executesql  @sql ,N ' @tid int,@topictitle nvarchar(60),
        @postdatetime datetime,@poster varchar(20),@posterid int ' ,
         @tid , @topictitle , @postdatetime , @poster , @posterid


         UPDATE   [ dnt_users ]   SET
                 [ lastpost ]   =   @postdatetime ,
                 [ lastpostid ]   =   @postid ,
                 [ lastposttitle ]   =   @title ,
                 [ posts ]   =   [ posts ]   +   1 ,
                 [ lastactivity ]   =   GETDATE ()
                 WHERE   [ uid ]   =   @posterid


         IF   @layer <= 0
         BEGIN
             UPDATE   [ dnt_topics ]   SET   [ replies ] = 0 , [ lastposter ] = @poster ,
                 [ lastpost ] = @postdatetime , [ lastposterid ] = @posterid  
                 WHERE   [ tid ] = @tid
         END
         ELSE
         BEGIN
             UPDATE   [ dnt_topics ]   SET   [ replies ] = [ replies ]   +   1 , [ lastposter ] = @poster ,
                 [ lastpost ] = @postdatetime , [ lastposterid ] = @posterid  
                 WHERE   [ tid ] = @tid
         END
     END

     UPDATE   [ dnt_topics ]   SET   [ lastpostid ] = @postid   WHERE   [ tid ] = @tid

     IF   @posterid   <>   - 1
     BEGIN
         INSERT   [ dnt_myposts ] ( [ uid ] ,  [ tid ] ,  [ pid ] ,  [ dateline ] ) 
             VALUES ( @posterid ,  @tid ,  @postid ,  @postdatetime )
     END

END


return   @posterid


GO

 

这里改成了sql动态语句,where后面是这样写的 WHERE [fid] in (' + @fidlist + ')'，这里用到了索引，有兴趣的朋友可以自己看看执行计划，优化后的效果如何呢，看图：

 

 

两图对比，差距还蛮大的，ok，发帖的优化到此结束。不过discuzNT的优化还远远没有结束。