DBSCAN(Density-Based Spatial Clustering of Applications with Noise)是一个比较有代表性的基于密度的聚类算法。与划分和层次聚类方法不同，它将簇定义为密度相连的点的最大集合，能够把具有足够高密度的区域划分为簇，并可在噪声的空间数据库中发现任意形状的聚类。C++实现代码，自定义扫描半径(eps)、最小包含点数(minPts)、维度。
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001372s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.059439s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001021s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001268s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001050s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003239s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000909s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003782s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014880s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001157s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 345542 [ RunTime:0.014980s ]
