contains和containsstable之间有显着差异吗?

时间:2010-11-17 18:59:24

标签: tsql full-text-search contains containstable

我在一个varchar(max)类型的列上创建了一个全文索引,并启用了文件流。文件流包含JPG,TIF,PDF和XML等数据(尽管这与问题无关,我相信)。

我创建了两个允许我搜索索引的查询。

全文搜索#1 -

select
      parentObj.ObjectID as 'GroupingID',
      parentObj.Name as 'Grouping',
      childObj.ObjectID as 'FileObjID', 
      childObj.Name as 'FileName',
      fs.FileStreamID
    from dbo.dat_FileStream fs
    inner join dbo.dat_Object childObj
        on fs.ObjectID = childObj.ObjectID
    inner join dbo.dat_Collection c
        on fs.ObjectID = c.ObjectID
    inner join dbo.dat_Object parentObj
        on c.ParentID = parentObj.ObjectID
    where contains(FileStreamData, @srchTerm)
        and parentObj.ObjectTypeID = 1
    ORDER BY 'Grouping'

全文搜索#2 -

select
      KEY_TBL.RANK,
      parentObj.ObjectID as 'GroupingID',
      parentObj.Name as 'Grouping',
      childObj.ObjectID as 'FileObjID',
      childObj.Name as 'FileName',
      fs.FileStreamID
    from dbo.dat_FileStream fs
    inner join containstable(dbo.dat_FileStream, FileStreamData, @srchTerm, 1000) as KEY_TBL
        on fs.FileStreamID = KEY_TBL.[KEY]
    inner join dbo.dat_Object childObj
        on fs.ObjectID = childObj.ObjectID
    inner join dbo.dat_Collection c
        on fs.ObjectID = c.ObjectID
    inner join dbo.dat_Object parentObj
        on c.ParentID = parentObj.ObjectID
    where parentObj.ObjectTypeID = 1
    ORDER BY 'Grouping'

两个全文搜索之间唯一显着的区别是查询#1使用包含而查询#2使用containsstable。

我的问题是两个查询并不总是产生相同的结果。例如,如果我搜索短语“独立承包商”,查询#1将产生10个不同文档(PDF和XML)的结果集,而查询#2只会产生6的结果集。这似乎是规则:查询#1总是比查询#2产生更多,而查询#2总是产生与查询#1完全相同的匹配。

查询#1 - 搜索“独立承包商”收益率:

4262    AAA-00-12   4561    AAA-00-12.pdf   4235
4316    AAA-00-15   4753    AAA-00-15.pdf   4427
4316    AAA-00-15   4754    AAA-00-15.xml   4428
3873    AAA-00-19   4784    AAA-00-19.pdf   4458
3903    AAA-00-22   6795    AAA-00-22.pdf   6459
3953    AAA-00-24   6899    AAA-00-24.pdf   6563
3953    AAA-00-24   6900    AAA-00-24.xml   6564
4842    AAA-00-9    4905    AAA-00-9.pdf    4577
4842    AAA-00-9    4906    AAA-00-9.xml    4578
4057    AAA-0001    4260    AAA-0001.pdf    3936

查询#2 - 搜索“独立承包商”收益率:

19  4262    AAA-00-12   4561    AAA-00-12.pdf   4235
126 4316    AAA-00-15   4754    AAA-00-15.xml   4428
126 4316    AAA-00-15   4753    AAA-00-15.pdf   4427
116 3873    AAA-00-19   4784    AAA-00-19.pdf   4458
125 3903    AAA-00-22   6795    AAA-00-22.pdf   6459
57  3953    AAA-00-24   6900    AAA-00-24.xml   6564
57  3953    AAA-00-24   6899    AAA-00-24.pdf   6563

1 个答案:

答案 0 :(得分:3)

CONTAINSTABLE

  

top_n_by_rank

     

指定只按最低排名匹配,按降序排列,   被退回。仅适用于   指定整数值n。 如果   top_n_by_rank与其他人合并   参数,查询可以返回   行数少于行数   实际上匹配所有的   谓词。

尝试使用w / o top运行,看看它是否与CONTAINS匹配。