mysql monitor queries

This article describes how to optimize a particular type of query.1. Optimize the count () queryThe count () aggregate function, and how to optimize queries that use the function, is probably one of the top 10 topics in MySQL that is most likely to be misunderstoodCount () is a special function that has two very different functions. It can count the number of values in a column or count the number of rows.T

Label:MySQL's "slow query" refers to an SQL statement that exceeds the maximum allowable query time ( long_query_time ), and the "unused index" query, by definition, is the SQL statement that the query statement does not use to the index.Slow query configuration and useAdd the following parameters to the Msyqld startup configuration file or command line parameters Long_query_time=1 Log-slow-queries=/var/

How MySQL uses temporary tables to accelerate queries This article describes how MySQL uses temporary tables to accelerate queries. Share it with you for your reference. The specific analysis is as follows: MySQL temporary tables can be used to accelerate

MySQL involves multi-table queries, You need to determine which connection method is more efficient Based on the query conditions. 1. cross join (Cartesian Product) or inner join [INNER | CROSS] JOIN 2. left outer join left [OUTER] JOIN or right outer join right [OUTER] JOIN. Specify the connection conditions WHERE, ON, and USING. PS: Basic JOIN usage First, assume there are two tables A and B. Their table

MySQL Slow Log on the company line, has not been well monitored. While I was idle last week, I wrote the monitoring script, and today I specially sent out the code to share with 51 Bo friends. for script annotations and the overall idea, I'll put it behind the script and explain it to you. #!/bin/bash## This script is used to monitor MySQL slow log changes wit

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Use ODBC to monitor Oracle Database (11.2.0.3) and MySQL database under Zabbix1. Monitor MySQL Database1) Installing ODBCYum-y Install UnixODBC Unixodbc-develYum Install Mysql-connector-odbc2) odbcinst-j View configuration fileUnixODBC 2.2.14DRIVERS ...:/etc/odbcinst.ini...S

Script Monitoring Database Master-Slave synchronizationSource: http://oldboy.blog.51cto.com/2561410/1632876Source:(production case): monitor MySQL master-slave synchronization is abnormal, if abnormal, send sms or mail to the administrator. Note: If there is no master-slave synchronization environment, you can use the following text in the file to read to simulate:Phase 1: Develop a daemon script to detect

See: http://blog.yemou.net/article/query/info/tytfjhfascvhzxcyt344Multi-performance applications will decompose the associated query. Simply, you can make a single-table query for each table, and then associate the results in your application. For example, the following query:Can be decomposed into the following queries instead:Why on earth do you do this? At first glance, this does not do any good, originally a query, here has become a number of

As Web applications become increasingly complex, simple MySQL + Memcached seems to be unable to meet the needs of data storage. Some enterprises have switched to NoSQL solutions, such as MongoDB, CouchDB, TokyoCabinet/Tyrant, and Cassandra. In their opinion, if the data access mode is not very complex, SQL databases will not be used. However, DeNA chose the "only MySQL" solution and achieved far better perf

Java connects, queries, and modifies the MySQL database0. General process:(1) Call the Class.forName () method to load the driver.(2) Call the Getconnection () method of the DriverManager object to obtain a connection object.(3) Create a statement object and prepare an SQL statement that can be a statement object (the statement executed immediately), A PreparedStatement statement (a precompiled statement) o

developers' intuition. Fortunately, databases like MySQL come with some assistance tools. This article briefly discusses the three tools: Using indexes, analyzing queries using EXPLAIN, and adjusting the internal configuration of MySQL. I. Using Indexes MySQL allows you to index database tables so that you can quickly