data in that result set by using the data in the resulting dataset as a filter to the next table, and then merges the results. If there is a third participating join, then the join result set of the previous two tables is used as the base data for the join, once again querying the data by looping through the criteria to the third table. Conclusion: The data volume of the driver table (preceding table) determines the total number of scans. 2. From the business It's all a full table scan, and
), Max_connection_error (maximum number of errors) settings, set according to the size of the business volume.
In addition, Open_files_limit, Innodb_open_files, Table_open_cache, Table_definition_cache can be set about 10 times times the size of max_connection.
Key_buffer_size recommended small, 32M or so, it is also recommended to close the query cache.
Mp_table_size and max_heap_table_size set not too large, in addition Sort_buffer_size, Join_buffer_size, Read_buffer_size, Read_rnd
;bind_param("s",$state); //执行 $stmt->execute(); //绑定结果 $stmt->bind_result($username); //移动游标 $stmt->fetch(); printf("%sisfrom%s\n",$username,$state); $stmt->close(); }
C. Non-buffered queries Normally, when you execute an SQL statement in your script, your program will stop there until the SQL statement is returned, and your program continues to execute. You can use unbuffered queries to change this behavior. In this case, there is a very
Tags: mysql new master-slave promotion from the mainThe day before yesterday to customers to do a database server adjustment, the previous one host abandoned, one from the library to promote the main, and then new to join other slave, here to record the operation steps:First, the old master library is turned on for read-only so that later steps are rolled back: Flush tables with read lockSecond, 110.10.1.102 upgrade to the main library, pause synchron
required to cache all the data on the disk into memory. Data preheating can improve read speed.For the InnoDB database, the data can be warmed up in the following ways:1. Save the following script as Makeselectqueriestoload.sqlSELECT DISTINCTCONCAT (' SELECT ', ndxcollist, ' from ', db, '. ', TB,' ORDER by ', Ndxcollist, '; ') SelectquerytoloadcacheFrom(SELECTEngine,table_schema Db,table_name TB,Index_name,group_concat (column_name ORDER by Seq_in_in
Buffer"->: "10.4.3 Sort Buffer and Join Buffer"
From ochefRecommendation sequence 2Original article: "Blog: http://www.orawh.com /"->: "Blog: http://www.ixdba.com /"
P18Original article: "such as update, delte, insert, create"->: "Such as update, delete, insert, and create"
Latest Update: 2009.10.19
From: Jasper CheP108Original article: "TL_WRITE_ALLOW_WRITE"->: "WRITE_ALLOW_WRITE"Original article: "P108 L7 concurrent Current read lock is the lock type of Read_NO_INSERT"->: "At the same time, C
This article does not involve the complex underlying data structure, through explain to explain SQL, and according to the possible situation, to do the specific optimization, so that the Tens Table Association query first page results can be completed in 2 seconds (real business alarm system optimization results). Queries that need to be optimized: Using explain appears with a using temporary, a using filesort with pagination means that you cannot use an index, and you need to adjust the stateme
Original: http://bbs.landingbj.com/t-0-246222-1.html http://bbs.landingbj.com/t-0-245851-1.htmlOptimization of the MyISAM storage engine in MySQL performance tuning.The points to consider in optimizing the MyISAM storage engine are as follows:As far as possible index, MyISAM only cache index does not cache data;Adjust read-Write priority according to actual demand;Delay insertion, use Insert delay, reduce and SELECT competeData order operation, let in
Tags: ref my.cnf mysqld State Hardware connection number file descriptor world further[MySQL performance diagnostics and tuning] LAMP System Performance Tuning, part 3rd: MySQL Server Tuning Http://www.ibm.com/developerworks/cn/linux/l-tune-lamp-3.html LoadRunner monitoring
Share a MySQL database shard backup script (original) and a mysql database shard backup script
Share a MySQL database shard backup script (original)
Development ideas:
1. path: Specify the backup location and define the path (firs
ObjectiveThere was no blog for a while, all day busy, to work, recording courses, happened recently a relatively idle time, to get the MySQL database.About MySQL database, here do not do too much introduction, open source, free and other features favored by various internet industry, especially after some large e-commerce applications, it is highly respected.There was a time in front of me writing a
mysql performance tuning considerations and Indexing One: Optimization of the database1 impact of business needsFor example, posts in the Forum statistics, and real-time updates from a functional command select count ( * from can get results if the forum generates thousands of posts per second, we don't use MyISAM The store uses the innodb storage; Even the best devices are not likely to be
number of times is exceeded 4.fail_timeout:max_fails times the time of the pause after the failure. 5.backup: When all other non-backup machines are down or busy, Request the backup machine. So the pressure on this machine is the lightest. Nginx supports multiple sets of load balancing at the same time, which is used for unused servers.Client_body_in_file_only set to On can speak the client post data logged to the file to do debugClient_body_temp_path setting a directory of record files ca
MySQL batch insert data script, mysql insert script
MySQL batch insert data script
#! /Bin/bashi = 1; MAX_INSERT_ROW_COUNT = $1; while [$ I-le $ MAX_INSERT_ROW_COUNT] do mysql-uroot-p
Simple Mysql backup BAT script sharing in Windows and mysql backup bat script
Preface
This document describes a simple BAT script for Mysql backup in Windows.MysqldumpCommand to back up a specified
How to run the script in mysql, mysql run the script
Suppose you want to run the Script: F: \ hello world \ niuzi. SQL
Method 1:In the command line (Database not connected), enter mysql-h localhost-u root-p Method 2:In the comma
xf master# cd major-mysqltuner-perl-993bc18/#./ mysqltuner.pl You will receive detailed reports and recommended tips for MySQL usage. The following is an example of the output from the default MariaDB installation: MySQL Performance Optimization 15. Optimize and Repair MySQL database Sometimes tables in the MYSQL/MA
MySQL database Regular automatic backup script, mysql database scriptThe most important thing for a Web system is the security and integrity of the database.It is very important to back up data regularly. Do not be lazy on this issue. If your important data is lost, it will make you cry.Export table structure and data mysqldump-uroot-pmypassword -- databases fans
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