mysql query optimizer tool online

Percona-toolkit, the effect 650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M02/79/9B/wKiom1aWAoHj2IpMAAERCq7ubOo745.png "title=" Screenshot.png "alt=" Wkiom1awaohj2ipmaaercq7uboo745.png "/> Progress bar went to 100%, then obtained" percona-toolkit.rpm ", this time Rpm-iv H percona-toolkit.rpm, you will see the installation progress. After installation, you can use the Pt-query-digest--help to check if the Help file is displayed, then it pro

Label:1. Use the explain statement to see if the index is used:EXPLAIN SELECT * from tb1_name WHERE 1 = 02. The WHERE clause below illustrates how this works. In the first row, the optimizer simplifies expression 4/2 to a value of 2, and then uses the index on My_col to quickly find values that are less than 2. In the second expression, MySQL must retrieve the My_col value of each row, multiply by 2, and co

Label: The following reasons may cause the MySQL optimizer to choose the wrong execution plan: A: The statistics are inaccurate,MySQL relies on the statistics provided by the storage engine to evaluate the costs, but some of the information provided by the storage engine is accurate, and some of the engines may have a large bias, such as:InnoDB because of its MVC

and will cause a lot of memory fragmentation, the related parameter setting will be introduced later.Make reasonable use of query cacheWith the pros and cons of query cache, using query cache wisely can make it an advantage and effectively avoid its disadvantages.1. Not all tables are suitable for use with query cache

Pt-Online-schema-change of MySQL online DDL Tool MySQL DDL:DDL is a feature that makes all MySQL ddbas criticized, because in MySQL, when dDDL is performed on a table, it locks the tabl

Tags: www sch contains lan Linux usr hang strong andPick to: This paper describes the problemof MySQL DDL , thept-online-schema-change of the work principle , and the actual use of The pt-online-schema-change tool modifies the 160 million-level data table structure on-line in the production environment. in a software

Online encoding query tool, encoding query, HTML Encoding [Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

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Baidu Webmaster Tools Baidu Index Query tool upgrade version of the 26th, the face of such a long time in the beta has a lot of people also tasted the sweetness, when it comes to upgrades, who can think of a tool upgrade is undoubtedly added some function or change some of the show form. Below I talk about the upgraded Baidu Index volume

Simple MySQL optimization tool-slow query and mysql optimization tool Slow Query First, enabling slow queries is a prerequisite regardless of the optimization. The slow query Mechanism

PHP tool-type MySQL add, delete, modify, and query tool-type mysql ? Php header ("content-type: text/html; charset = UTF-8 "); class DBUtils {/*** General update method insert update delete operation * @ param SQL * @ return bool true false */public function update ($ SQL) {

... ########################################### [100%]1:mysql-administrator ########################################### [100%][Email protected] mysql]#Continue to install Mysql-query-browser, the beginning of the package[Email protected] mysql]# RPM-IVH

GitHub has officially announced the release of Gh-ost:github's MySQL no-trigger online Change table Definition tool in open source mode!Gh-ost was developed by GitHub in recent months to address a frequently encountered problem: changing product requirements constantly require changes to the MySQL table structure. Gh-o

,Address varchar (+) Default ' Shenzhen ',Year Date); End of Build tableThe following is the Insert fieldInsert into teacher values (' ' ', ' Glchengang ', ' Shenzhen One ', ' 1976-10-10 ');Insert into teacher values (' ' ', ' Jack ', ' Shenzhen One ', ' 1975-12-23 ');Note: In the table under construction1. Set the ID to a numeric field of length 3: Int (3), and let it automatically add one to each record: auto_increment, and cannot be empty: NOT NULL, and let him be the main field primary key.2

.log (7) Save the query to the Query_review table PT-query-digest--user=root–password=abc123--review h=localhost,d=test,t=query_review--create-review-Table Slow.log (8) Save the query to the Query_history table PT-query-digest--user=root–password=abc123--review H=localhost,d=test,t=query_ history--create-review-Table s

A BackgroundLast year, a MySQL trace replay test, due to the performance schema itself to collect sample length and other limitations, the actual playback of the success rate is relatively low.Recently found an open source tool, based on tcpcopy implementation of online traffic simulation test, this open source tool is

its interpretation of the rename. By default Gh-ost does not proceed to execute. This flag tells Gh-ost to skip the renamed columns, i.e. to treat what gh-OST thinks is renamed columns as unrelated columns. Note:you may lose column data-approve-renamed-Columns ALTERinch CaseYour ALTER statement renames columns, Gh-ost would note that and an offer to its interpretation of the rename. By default Gh-ost does not proceed to execute. This flag approves that Gh-ost's interpretation si correct-assume

System performance tuning in particular MySQL database tuning a primary basis is the slow query log. Originally there is a powerful tool on Ubantu or CentOS is Percona Toolkit, then how to use Pt-query-digest on Mac?Download Percona ToolkitAccess Http://www.percona.com/downloads/percona-toolkit, use source code install

/host_name-slow.log# Log all queries without indexes# log-queries-not-using-indexes# Log only queries which examine at least N rows (>= 5.1.21)# min_examined_row_limit=1000 # default: 0# Log slow OPTIMIZE TABLE, ANALYZE TABLE, and ALTER TABLE statements# log-slow-admin-statements# Log slow queries executed by replication slaves (>= 5.1.21)# log-slow-slave-statements# MySQL 5.1.6 through 5.1.20 had a default value of log-output=TABLE, so you should fo

--incremental-basedir=/home/backup/all/alldb/home/backup/daily/daily_20120409 2>>/home /backup/daily/dailybackup_$tday.log 2.5 Incremental Recovery (1) • Extract Files • Full recovery first, then incremental recovery • (1): First restore full standby innobackupex--apply-log--user=root--defaults-file=/data/mbdata/my.cnf--no-lock/ Home/backup/all/alldbPS:/home/backup/all/alldb is a full-scale backup directory • (2): Restore incremental backup Innobackupex/home/backup/all/alldb--in