关键词匹配项目深入研究（二）- 分表思想的引入，关键词深入研究

（二）分表思想的引入

近期的文章： 1）高并发数据采集的架构应用（Redis的应用）

2）高可用数据采集平台（如何玩转3门语言php+.net+aauto）

手把手教你做关键词匹配项目这块基本已经完成，深入研究是对系统的性能作为分析，在一些环境的刺激下所必需要做的一些改变。

手把手教你做关键词匹配项目: 手把手教你做关键词匹配项目（搜索引擎）---- 第一天~手把手教你做关键词匹配项目（搜索引擎）---- 第二十二天 (共22篇)

深入研究：上节讲到关键词匹配项目深入研究-过滤器的引入。

每一篇会分为问题的前因、解决方案以及有些必要的实现方案。

本篇正文正式开始。

问题的前因

随着自动采集数据的爆炸式的增长，词库的容量蒸蒸日上，一下从几W数据猛增几百万数据，小帅帅看着数据库的查询越来越感到无能为力。

再加上小丁丁常对小帅帅说的最多的一句：何时那么选词能快一点，每次我都等好久都莫有反应，真是急死我了。

小帅帅也比较焦急，心力憔悴，真正的感觉到原来这就是挑战。小帅帅无可奈何的继续找到于老大，求于老大赏赐高招。

于老大拍拍小帅帅的肩膀：小伙子，知道项目的难度了吧！

小帅帅回答道：别挖苦我了，我已深深的感受到了，我想我心脏估计快承受不了了。

于老大：就这点你就承受不了，那估计以后有的是给你受的。

小帅帅：大哥，别说这些虚的行不，赶紧的解决方案丫。

于老大：急啥，事情是急不来的，过来，哥给你指条明路。

“每个宝贝是不是有类别的属性，那么这几百万数据真正属于这个类别的词能够有多少？假设我们只取这个类别的词库我们的项目是否可以继续稳定下来”。

解决方案

按照某种业务需要，我们可以对数据表实行分割，可以纵向或者横向分割，可以有效的进行性能优化。

纵向分割也称列分割，把不常用的列或者长字段分割来保证实体处于一个相对适用的状态，常见的有一对一关联。

横向分割也称行分割，按照某种业务拆分数据的记录来存放在不同的表，常见的有按日期分表操作。

本案例是使用横向分割，把数据按照类别的形式进行拆分。

实现方案

我们为了不更改数据表的结构，这样设计了，我们按照表名来区分项目使用那个数据表。这样一来的改动相对是非常少的。我们只需稍微改动下代码就可以解决了，这很心塞的一件事情。

修改Keyword的代码，增加获取数据源。

<?<span>php
</span><span>define</span>('DATABASE_HOST','127.0.0.1'<span>);
</span><span>define</span>('DATABASE_USER','xiaoshuaishuai'<span>);
</span><span>define</span>('DATABASE__PASSWORD','xiaoshuaishuai'<span>);
</span><span>define</span>('DATABASE_CHARSET','utf-8'<span>);

</span><span>class</span><span> Keyword {

    </span><span>public</span> <span>$word</span><span>;

    </span><span>public</span> <span>static</span> <span>$conn</span> = <span>null</span><span>;

    </span><span>public</span> <span>function</span><span> getDbConn(){
        </span><span>if</span>(self::<span>$conn</span> == <span>null</span><span>){
            self</span>::<span>$conn</span> = <span>mysql_connect</span>(DATABASE_HOST,DATABASE_USER,<span>DATABASE__PASSWORD);
            </span><span>mysql_query</span>("SET NAMES '".DATABASE_CHARSET."'",self::<span>$conn</span><span>);
            </span><span>mysql_select_db</span>("dict",self::<span>$conn</span><span>);
            </span><span>return</span> self::<span>$conn</span><span>;
        }
        </span><span>return</span> self::<span>$conn</span><span>;
    }


    </span><span>public</span> <span>function</span><span> save(){

        </span><span>$sql</span> = "insert into keywords(word) values ('<span>$this</span>->word')"<span>;
        </span><span>return</span> <span>mysql_query</span>(<span>$sql</span>,<span>$this</span>-><span>getDbConn());
    }

    </span><span>public</span> <span>static</span> <span>function</span> getWordsSource(<span>$cid</span>,<span>$limit</span>=0,<span>$offset</span>=40<span>){
        </span><span>$sql</span> = "SELECT * FROM　keywords_<span>$cid</span> LIMIT <span>$limit</span>,<span>$ffset</span>"<span>;
        </span><span>return</span> DB::MakeArray(<span>$sql</span><span>);
    }

    </span><span>public</span> <span>static</span> <span>function</span> getWordsCount(<span>$cid</span><span>){
          </span><span>$sql</span> = "SELECT count(*) FROM　keywords_<span>$cid</span>"<span>;
        </span><span>return</span> DB::QueryScalar(<span>$sql</span><span>);

    }

}</span>

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DB类新增QueryScalar，用于算总量

<?<span>php
</span><span>#</span><span>@author oShine</span>
<span>define</span>('DATABASE_HOST','127.0.0.1'<span>);
</span><span>define</span>('DATABASE_USER','xiaoshuaishuai'<span>);
</span><span>define</span>('DATABASE__PASSWORD','xiaoshuaishuai'<span>);
</span><span>define</span>('DATABASE_CHARSET','utf-8'<span>);

</span><span>class</span><span> DB {

    </span><span>public</span> <span>static</span> <span>$conn</span> = <span>null</span><span>;

    </span><span>public</span> <span>static</span> <span>function</span><span> Connect(){
        </span><span>if</span>(self::<span>$conn</span> == <span>null</span><span>){
            self</span>::<span>$conn</span> = <span>mysql_connect</span>(DATABASE_HOST,DATABASE_USER,<span>DATABASE__PASSWORD);
            </span><span>mysql_query</span>("SET NAMES '".DATABASE_CHARSET."'",self::<span>$conn</span><span>);
            </span><span>mysql_select_db</span>("dict",self::<span>$conn</span><span>);
            </span><span>return</span> self::<span>$conn</span><span>;
        }
        </span><span>return</span> self::<span>$conn</span><span>;
    }

    </span><span>public</span> <span>static</span> <span>function</span> Query(<span>$sql</span><span>){
       </span><span>return</span> <span>mysql_query</span>(<span>$sql</span>,self::<span>Connect());
    }

    </span><span>public</span> <span>static</span> <span>function</span> makeArray(<span>$sql</span><span>){
        </span><span>$rs</span> = self::Query(<span>$sql</span><span>);
        </span><span>$result</span> = <span>array</span><span>();
        </span><span>while</span>(<span>$data</span> = <span>mysql_fetch_assoc</span>(<span>$rs</span><span>)){
            </span><span>$result</span>[] = <span>$data</span><span>;
        }
        </span><span>return</span> <span>$result</span><span>;
    }

    </span><span>public</span> <span>static</span> <span>function</span> QueryScalar(<span>$sql</span><span>){
         </span><span>$rs</span> = self::Query(<span>$sql</span><span>);
         </span><span>$data</span> = <span>mysql_fetch_array</span>(<span>$rs</span><span>);
         </span><span>if</span>(<span>$data</span> == <span>false</span> || <span>empty</span>(<span>$data</span>) || !<span>isset</span>(<span>$data</span>[1])) <span>return</span> 0<span>;
         </span><span>return</span> <span>$data</span>[1<span>];
    }
} </span>

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修改Selector的代码，用于选词：

<?<span>php
</span><span>#</span><span>@Filename:selector/Selector.php</span><span>
#</span><span>@Author:oshine</span>

<span>require_once</span> <span>dirname</span>(<span>__FILE__</span>) . '/SelectorItem.php'<span>;
</span><span>require_once</span> <span>dirname</span>(<span>__FILE__</span>) . '/charlist/CharList.php'<span>;
</span><span>require_once</span> <span>dirname</span>(<span>__FILE__</span>) . '/charlist/CharlistHandle.php'<span>;
</span><span>require_once</span> <span>dirname</span>(<span>dirname</span>(<span>__FILE__</span>)) . '/lib/Logger.php'<span>;

</span><span>class</span><span> Selector
{

    </span><span>private</span> <span>static</span> <span>$charListHandle</span> = <span>array</span><span>(
        </span>"黑名单" => "BacklistCharListHandle",
        "近义词" => "LinklistCharListHandle"<span>
    );

    </span><span>public</span> <span>static</span> <span>function</span> select(<span>$num_iid</span><span>)
    {
        </span><span>$selectorItem</span> = SelectorItem::createFromApi(<span>$num_iid</span><span>);

        Logger</span>::trace(<span>$selectorItem</span>-><span>props_name);

        </span><span>$charlist</span> = <span>new</span><span> CharList();

        </span><span>foreach</span> (self::<span>$charListHandle</span> <span>as</span> <span>$matchKey</span> => <span>$className</span><span>) {

            </span><span>$handle</span> = self::createCharListHandle(<span>$className</span>, <span>$charlist</span>, <span>$selectorItem</span><span>);
            </span><span>$handle</span>-><span>exec</span><span>();

        }

        </span><span>$selectWords</span> = <span>array</span><span>();

        </span><span>$wordsCount</span> = Keyword::getWordsCount(selectorItem-><span>cid);
        </span><span>$offset</span> = 40<span>;
        </span><span>$page</span> =  <span>ceil</span>(<span>$wordsCount</span>/<span>$offset</span><span>);
        </span><span>for</span>(<span>$i</span>=0;<span>$i</span><=<span>$page</span>;<span>$i</span>++<span>){
            </span><span>$limit</span> = <span>$i</span>*<span>$offset</span><span>;
            </span><span>$keywords</span> = Keyword::getWordsSource(selectorItem->cid,<span>$limit</span>,<span>$offset</span><span>);
             </span><span>foreach</span> (<span>$keywords</span> <span>as</span> <span>$val</span><span>) {
                </span><span>#</span><span> code...</span>
                <span>$keywordEntity</span> = SplitterApp::<span>split</span>(<span>$val</span>["word"<span>]);
                
                    </span><span>#</span><span> code...</span>
                <span>if</span>(MacthExector::macth(<span>$keywordEntity</span>,<span>$charlist</span><span>)){
                    </span><span>$selectWords</span>[] = <span>$val</span>["word"<span>];
                }          

            }
        }

        </span><span>return</span> <span>$selectWords</span><span>;
    }

    </span><span>public</span> <span>static</span> <span>function</span> createCharListHandle(<span>$className</span>, <span>$charlist</span>, <span>$selectorItem</span><span>)
    {
        </span><span>if</span> (<span>class_exists</span>(<span>$className</span><span>)) {
            </span><span>return</span> <span>new</span> <span>$className</span>(<span>$charlist</span>, <span>$selectorItem</span><span>);
        }
        </span><span>throw</span> <span>new</span> <span>Exception</span>("class not exists", 0<span>);
    }
}</span>

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总结
小帅帅又学到了新的知识点，这是要犒劳于老大的节奏吗？你们是否也要犒劳下我呢，求赞哈！