mysql performance tuning tools

some keys, the values can be retrieved from the index tree for faster.Assume that you issue the following SELECT statement:Mysql> SELECT * from Tbl_name WHERE col1=val1 and Col2=val2; If a multi-column index exists on col1 and col2, the appropriate row can be fetched directly. If separate single-row column indexes exist on col1 and col2, the optimizer tries to find a more restrictive index by deciding which index will find fewer rows and using that index to fetch rows.When setting the Tmp_table

MySQL Performance tuning: The speed of the insert query: The time to insert a record consists of the following: Connection: (3) Send query to server: (2) Analysis of the query: (2) Insert Record: (1 x record size) Insert Index: (1 x index) Off: (1) The numbers here are a bit proportional to the overall time. This does not take into account the initial co

|+-----------------------+-------------+| Handler_read_first | 5803750 || Handler_read_key | 6049319850 || Handler_read_next | 94440908210 || Handler_read_prev | 34822001724 || Handler_read_rnd | 405482605 || Handler_read_rnd_next | 18912877839 |+-----------------------+-------------+ Number of query requests paged out by the server: mysql> show global status like ' Com_select '; +---------------+-----------+| variable_name | Value |+---------------

Mysql Tomcat C3p0 System Performance Tuning personal summary, System Information The application logic is to use c3p0 to query data in the database and return Json data over http. 1. the initial test result JMeter test result before optimization No. Type Original 1000 data bigger 1 500 Connection 250 query/S 63q/S70q/S

you to optimize the SQL statement for join. Also, the fields that are used for join should be of the same type. For example, if you want to join a DECIMAL field with an INT field, MySQL cannot use its index. For those string types, you also need to have the same character set. (The character set of two tables may be different) "Avoid select *" "always set an ID for each table" We should set an ID for each table in the database as its primary key, a

, where sending data accounts for 99% of the time. Still more than the initial page load time. Finally, instead of innerjoin the table with the select method to remove the relevant data, leftjoin the table data, by looping the select result set, the data is obtained separately. After the modified development environment page load time is 0.2~0.3s, the server environment is 0.4~0.5s. Although not ideal, performance is acceptable for small systems withi

add the following line to the boot auto mount in the/etc/fstab file: /dev/sdb1/ssd ext3 defaults00 Now we move MySQL to the new diskFirst stop the MySQL service: #service mysqld stop I suggest you?? Stop Apache/nginx at the same time to prevent any attempts to write to the database: #service httpd stop #service nginx stop Now copy the entire

MySQL Management: Performance tuning, high availability and monitoring mini-bookmysql5.5.x Main Improvements1. Use InnoDB storage engine by default2. Make full use of CPU multi-core processing capability3, improve the number of brush write dirty pages and merge the number of inserts, improve I/O4, let Innodb_buffer_pool buffer pool of heat data to survive longer,

MyBatisRemoving all the columns will make the optimizer unable to complete such optimizations as overwriting index scans, such as HibernateHowever, retrieving the query cache for all columns is more beneficial than multiple independent query caches that only get partial columnsEvery time I see a SELECT * Please wonder if you really need to take it all outDuplicate query for the same data: Please cache this data, for example, in the session.The simplest of three metrics to measure query overhead

Tags:/etc/serve linux show via experience performance help insertionMySQL restricts the size of packets accepted by the server according to the configuration file.Sometimes large inserts and updates are limited by the Max_allowed_packet parameter, resulting in failure.View current configurationShow VARIABLES like '%max_allowed_packet% ';The results shown are:+--------------------+---------+| variable_name | Value |+--------------------+---------+| Max

1. Macro-tuning can be considered three parts, respectively, hardware, network, software, the main consideration here is software tuning(1) Software tuning includes: table Design (Paradigm, field type, data storage engine), SQL statement Index, configuration file parameters, file system, operating system, MySQL version