postgresql performance tuning parameters

directory, and the file uses "host name-slow. log, but you can also specify a name for this option. 2. long_query_time The default value is 10 seconds. you can set it dynamically. The value ranges from 1 to on. if the database is started, the log is disabled by default. As of 5.1.21 and the version with the Google patch installed, this option can be set in microseconds. this is a great feature, because once you have eliminated all queries whose query time exceeds 1 second, the adjustment is ver

Tags: mysql monitoringMySQL performance and sys monitoring parameters in the MySQL5.71. Performance Schema: IntroductionIn MySQL5.7, the performance schema has been greatly improved, including the introduction of a large number of newly added monitoring items, reduced footprint and load, and a significant increase in e

will occur.Five. Summary1. With these four parameters, you can control how much dirty data is consumed in memory to write to the disk file system;2. How long the dirty data can exist in memory, and write to disk over this time;3. The amount of dirty data in memory of a single task is written to disk;The frequency at which the 4.pdflush kernel thread executes.Six. Note1. Distinguish between Dirty_background_ratio and dirty_ratio.2. Database systems OR

option can be set in microseconds. This is a great feature, because once you have eliminated all queries whose query time exceeds 1 second, the adjustment is very successful, which helps you eliminate the problem SQL before the problem increases. 3. log_queries_not_using_indexes Enabling this option is a good idea. It actually records the query that returns all rows. Summary We have introduced five categories of MySQL parameters. We usually seldom to

you've eliminated all queries for more than 1 seconds, the adjustment is very successful, which can help you eliminate the problem SQL before the problem becomes larger. 3, Log_queries_not_using_indexes It's a good idea to turn on this option, which actually records the query that returns all rows. Summary We introduced the MySQL parameters of the five types of settings, usually we rarely touch them, in the MySQL

Table_cache is a very important MySQL performance parameter, which is called Table_open_cache in the 5.1.3 version. Table_cache is primarily used to set the number of table caches. Because each client connection accesses at least one table, the value of this parameter is related to Max_connections. Caching mechanism When a connection accesses a table, MySQL checks the number of currently cached tables. If the table is already open in the cache, dire