3的倍数为什么会有这样的特征

页面:/news/view-591524/ | 耗时:0.9251 s | 内存:1.89 MB | 查询:4 | 缓存读取:4 写入:0 | 加载文件:23
select * from tbl_Articles WHERE ArticleID=591524 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=591524 LIMIT 0,1
select * from tbl_Articles_sphinx where id=591524 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(1042879,1081699,1099865,1067623,1081991,1108401,1047309,1073772,1049670,1063671,1089832,1104483,1114412,1110546,1078310,1073899,1106711,1062350,1130158,1113413,1114866,1067739,1104745,1117003,1086592,1096793,1054388,1084197,1072747,1102690) ORDER BY field (ArticleID,1042879,1081699,1099865,1067623,1081991,1108401,1047309,1073772,1049670,1063671,1089832,1104483,1114412,1110546,1078310,1073899,1106711,1062350,1130158,1113413,1114866,1067739,1104745,1117003,1086592,1096793,1054388,1084197,1072747,1102690)