mysql query performance tuning

Tags: set multi-line optimization name function official same scheme performanceIn database design, if the query is written badly, even if the library table structure design is reasonable, the index can not achieve high performance.1. Optimize data accessThe most basic reason for poor query performance is that there is

the index and data rows, and the distribution of the index.Due to inaccurate statistics, or the implementation mechanism of MySQL itself, in some cases, the cost of calculation is not accurate.The optimizations that MySQL can handle are: To redefine the order of associated tables Convert an outer join to an inner join Use equivalent transformation rules such as (5=5 and a> 5) to be rewritt

Label:Before very silly very naïve thought is nothing more than a distance, and then compare out on the line, and then when the access to a lot of users, and the database in the latitude information a lot of time, the rapid increase in computational capacity, can make the server completely stupid, or old-timer experience than we rich, gave me a great revelation.MySQL Performance tuning – distance calculatio

other is that we have not achieved our expected goal. We need to find performance bottlenecks and optimize the performance. 3. Performance Analysis Through the above performance test, we found that the website did not meet our expected performance goal. What we need to do i

Tags: div float SQL Time blog host Mail database service hrefPrepare can solve the large-volume Web site to the database server load and cost, this article through an example to introduce the pre-query prepare and the performance of ordinary query comparison, the need for friends can refer to. The instance code is as follows: PHPclassTimer { Public $StartTime= 0;

immediately after execution, and then the data is written to the hard disk when it is idle. More appropriate for logging.Straight_join: Defines the association order.Sql_small_result,sql_big_result: For querying, the size of the flag result set, the boot sort operation in memory or hard disk execution.Sql_buffer_result: Put the result of the query into a temporary table and release the table lock as soon as possible.Sql_cache,sql_no_cache: whether to

First look at the MSYQL logical framework: Images from high-performance MySQLIf Querycache is used, when the query receives one and the same query, the server retrieves the results from the query cache instead of parsing and executing the same query again. This can greatly i

MariaDB [(None)]> show processlist;+--------+--------+------------------+---------+-------------+---------+---------------+----------------------+ --------| Id | User | Host | db | Command | Time | State | Info | Progre| 287662 | Root | localhost:41583 | Finance | Query | 665767 | Sending Data | SELECT COUNT (*) from ' cash_beorder ' INNER JOIN ' Cash_account ' on (' Cash_beorder '. ' account_id ' = ' CA | 0.00| 287663 | Root | localhost:41626 | Fina

monitoring, it facilitates Performance Optimization after the product is launched.The other is that we have not achieved our expected goal. We need to find performance bottlenecks and optimize the performance.#3. Performance analysis ##Through the above performance test, we

MySQL Query performance optimizationThe optimization of MySQL query performance involves many aspects, including library table structure, establishing reasonable index and reasonable query