mysql - 随笔分类(第9页) - papering

读写分离与主从同步数据一致性

摘要：MySQL的读写分离与主从同步数据一致性 - windpoplar - 博客园 https://www.cnblogs.com/windpoplar/p/11978742.html MySQL的读写分离与主从同步数据一致性有没有做MySQL读写分离？如何实现mysql的读写分离？MySQL主从复制阅读全文

posted @ 2017-12-20 18:13 papering 阅读(361) 评论(0) 推荐(0)

mysql 查询语句去重通过sql去重

摘要：url 在表中具有唯一性；由于定时任务的多进程/代码的多线程/定时任务的调度/脚本的执行时间，导致，破坏了唯一性； SELECT COUNT(1) FROM test_error_tmpUNION ALL SELECT COUNT(DISTINCT url) FROM test_error_tmp 阅读全文

posted @ 2017-12-19 08:51 papering 阅读(1311) 评论(0) 推荐(0)

SHOW PROCESSLIST Syntax

摘要：https://dev.mysql.com/doc/refman/5.7/en/show-processlist.html SHOW PROCESSLIST shows you which threads are running. You can also get this information 阅读全文

posted @ 2017-12-08 19:15 papering 阅读(181) 评论(0) 推荐(0)

How MySQL Opens and Closes Tables refuse connections 拒绝连接的原因 file descriptors 最大连接数

摘要：实践： 1、 set GLOBAL max_connections=2048;show status like '%connections%'; 0-连接数不够：软件，增大max_connections； 1-系统资源不足：硬件，file descriptors 不足，改善硬件 MySQL :: M 阅读全文

posted @ 2017-12-08 19:12 papering 阅读(241) 评论(0) 推荐(0)

1250太小了 mysql 并发

摘要：SHOW VARIABLES LIKE '%connection%'; character_set_connection utf8mb4collation_connection utf8mb4_general_ciextra_max_connections max_connections 1250m 阅读全文

posted @ 2017-12-08 16:59 papering 阅读(210) 评论(0) 推荐(0)

mysql 5.6 bug

摘要：https://dev.mysql.com/doc/refman/5.6/en/account-management-sql.html USE mysql; SELECT Host,User FROM user; 【BUG】CREATE USER 'xx'@'%' IDENTIFIED BY 'yy 阅读全文

posted @ 2017-11-07 20:48 papering 阅读(271) 评论(0) 推荐(0)

The basic principle of test case 修改引擎

摘要：The basic principle of test case evaluation is that output resulting from running a test case is compared to the expected result. https://dev.mysql.co 阅读全文

posted @ 2017-11-07 17:35 papering 阅读(365) 评论(0) 推荐(0)

left outer join preserving unmatched rows from the first table

摘要：https://docs.oracle.com/javadb/10.8.3.0/ref/rrefsqlj18922.html INNER JOIN operation Specifies a join between two tables with an explicit join clause. 阅读全文

posted @ 2017-11-04 22:28 papering 阅读(230) 评论(0) 推荐(0)

install mysql firewall

摘要：![](http://images2015.cnblogs.com/blog/1006507/201706/1006507-20170606174513918-1891300933.png) 阅读全文

posted @ 2017-06-06 17:46 papering 阅读(133) 评论(0) 推荐(0)

本地数据库访问远程数据库 Federated

摘要：mysql 阅读全文

posted @ 2017-06-05 12:29 papering 阅读(146) 评论(0) 推荐(0)

mysql group by 去重分类求和

摘要：w 分类统计去重 SELECT MIN(id) as min_id ,COUNT(1) AS c FROM parent_url_copy GROUP BY CONCAT(page_url,children_url) 阅读全文

posted @ 2017-05-10 12:12 papering 阅读(3019) 评论(0) 推荐(0)

10.6 Comment Syntax

摘要：w https://dev.mysql.com/doc/refman/5.7/en/comments.html MySQL 5.7 Reference Manual / Language Structure / Comment Syntax 10.6 Comment Syntax MySQL Ser 阅读全文

posted @ 2017-05-06 11:51 papering 阅读(215) 评论(0) 推荐(0)

InnoDB Crash Recovery InnoDB崩溃恢复

摘要：w 阅读全文

posted @ 2017-05-05 23:24 papering 阅读(240) 评论(0) 推荐(0)

COUNT(*) vs COUNT(col)

摘要：w https://www.percona.com/blog/2007/04/10/count-vs-countcol/ 阅读全文

posted @ 2017-05-05 14:42 papering 阅读(160) 评论(0) 推荐(0)

page size

摘要：https://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_page_size https://dev.mysql.com/doc/refman/5.7/en/innodb-file-space.html 15.12.2 File Space 阅读全文

posted @ 2017-05-05 00:54 papering 阅读(402) 评论(0) 推荐(0)

清除查询缓存

摘要：清除查询缓存阅读全文

posted @ 2017-04-28 13:49 papering 阅读(170) 评论(0) 推荐(0)

多进程重复写值

摘要：w https://dev.mysql.com/doc/refman/5.7/en/lock-tables.html MySQL enables client sessions to acquire table locks explicitly for the purpose of cooperat 阅读全文

posted @ 2017-04-27 09:56 papering 阅读(207) 评论(0) 推荐(0)

Avoiding Full Table Scans

摘要：w MySQL :: MySQL 5.7 Reference Manual :: 9.2.1.19 Avoiding Full Table Scanshttps://dev.mysql.com/doc/refman/5.7/en/table-scan-avoidance.html 阅读全文

posted @ 2017-04-26 11:01 papering 阅读(129) 评论(0) 推荐(0)

do not use numbers as enumeration values

摘要：w 字段类型设置错误有限元的判断，勿用枚举行。 MySQL :: MySQL 5.7 Reference Manual :: 12.4.4 The ENUM Typehttps://dev.mysql.com/doc/refman/5.7/en/enum.html We strongly reco 阅读全文

posted @ 2017-04-21 16:33 papering 阅读(194) 评论(0) 推荐(0)

MySQL大表优化方案

摘要：w MySQL大表优化方案 - 码农 - SegmentFaulthttps://segmentfault.com/a/1190000006158186 阅读全文

posted @ 2017-04-19 20:36 papering 阅读(137) 评论(0) 推荐(0)

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随笔分类 - mysql