zoukankan      html  css  js  c++  java

  • How MySQL Uses Indexes CREATE INDEX SELECT COUNT(*)

    MySQL :: MySQL 5.7 Reference Manual :: 9.3.1 How MySQL Uses Indexes
    https://dev.mysql.com/doc/refman/5.7/en/mysql-indexes.html

     CREATE INDEX   SELECT COUNT(*)

    CREATE INDEX windex_countrycode ON sales_rank (countrycode);
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);

[SQL]
CREATE INDEX windex_countrycode ON sales_rank (countrycode);
受影响的行: 1150091
时间: 36.351s

[SQL]
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
受影响的行: 1150091
时间: 37.230s

[SQL]
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
受影响的行: 1150091
时间: 41.205s

[SQL]
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);
受影响的行: 1150091
时间: 42.972s


ALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 42.791s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 42.540s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 40.466s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 36.134s

    SELECT COUNT(*) FROM sales_rank;

    1150091

    CREATE INDEX windex_countrycode ON sales_rank (countrycode);
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);

[SQL]
CREATE INDEX windex_countrycode ON sales_rank (countrycode);
受影响的行: 1150091
时间: 38.098s

[SQL]
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
受影响的行: 1150091
时间: 39.191s

[SQL]
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
受影响的行: 1150091
时间: 38.382s

[SQL]
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);
受影响的行: 1150091
时间: 39.717s
    ALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 40.228s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 37.649s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.389s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.135s
    CREATE INDEX windex_countrycode ON sales_rank (countrycode);
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);

[SQL]
CREATE INDEX windex_countrycode ON sales_rank (countrycode);
受影响的行: 1150091
时间: 36.486s

[SQL]
CREATE INDEX windex_grab_amz_date ON sales_rank (grab_amz_date);
受影响的行: 1150091
时间: 39.930s

[SQL]
CREATE INDEX windex_categoryid ON sales_rank (categoryid);
受影响的行: 1150091
时间: 40.498s

[SQL]
CREATE INDEX windex_grab_rank ON sales_rank (grab_rank);
受影响的行: 1150091
时间: 40.745s
    ALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251sALTER TABLE sales_rank DROP INDEX windex_countrycode;
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_countrycode;
受影响的行: 1150091
时间: 41.601s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_amz_date;
受影响的行: 1150091
时间: 39.273s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_categoryid;
受影响的行: 1150091
时间: 36.664s

[SQL]
ALTER TABLE sales_rank DROP INDEX windex_grab_rank;
受影响的行: 1150091
时间: 35.251s
  • 相关阅读:
    I/O会一直占用CPU吗？【转载】
    CPU和线程的关系
    future封装了callable，thread封装future。
    （转）Java中的守护线程
    线程中sleep方法和wait方法有什么区别？(转)
    Java异常---获取异常的堆栈信息
    分析iOS Crash文件，使用命令符号化iOS Crash文件
    String Matching（poj1580）
    U转串口驱动安装
    [LNU.Machine Learning.Question.1]梯度下降方法的一些理解
  • 原文地址：https://www.cnblogs.com/rsapaper/p/6203408.html
Copyright © 2011-2022 走看看