I am currently trying to migrate a system to postgres and I am unfortunately not able to understand why a specific query is running so incredibly slow. Both in Transact-SQL and Oracle the same query runs in under 200ms. First things first though, I have a big table with14.000.000 entries...
https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/performance/troubleshoot-slow-running-queries https://erikdarling.com/monitoring-sql-server-for-query-timeouts-with-extended-events/ https://sqlmaestros.com/free-sql-video-troubleshoot-slow-running-query-sql-server-extended-events-wa...
Questions 发往服务器的查询的数量。 Slow_queries 要花超过long_query_time时间的查询数量。 Threads_connected 当前打开的连接的数量。 Threads_running 不在睡眠(激活)的线程数量。 Uptime 服务器工作了多少秒。 Uptime_since_flush_status 最近一次使用FLUSH STATUS 的时间(以秒为单位) (3)最后,可以尝试kill id(...
SQL Server查找哪些执行慢的语句 1、根据 https://learn.microsoft.com/zh-cn/troubleshoot/sql/database-engine/performance/troubleshoot-slow-running-queries网址提供的脚本。 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 SELECT req.session_id , req.total_elapsed_timeASduration_ms , req.cpu_time...
slow_query_log=1 ## 文件位置及名字 slow_query_log_file=/data/mysql/slow.log ## 设定慢查询时间 long_query_time=0.4 ## 没走索引的语句也记录 log_queries_not_using_indexes vim /etc/my.cnf slow_query_log=1 slow_query_log_file=/data/mysql/slow.log ...
Running vs. Waiting: why are queries slow?If you find queries that exceed your predefined threshold, examine why they could be slow. The cause of performance problems can be grouped into two categories, running or waiting:WAITING: Queries can be slow because they're waiting on a bottl...
Slow SQL queries in ApsaraDB for ClickHouse,ApsaraDB for ClickHouse:If your ApsaraDB for ClickHouse cluster encounters performance issues or when you perform periodic maintenance, you can view slow SQL queries to troubleshoot the issues. This topic descr
slow_query_log=1 ## 文件位置及名字 slow_query_log_file=/data/mysql/slow.log ## 设定慢查询时间 long_query_time=0.4 ## 没走索引的语句也记录 log_queries_not_using_indexes vim /etc/my.cnf slow_query_log=1 slow_query_log_file=/data/mysql/slow.log ...
官方文档有着这样的解释:table_open_cache is related to max_connections. For example, for 200 concurrent running connections, specify a table cache size of at least 200 * N, where N is the maximum number of tables per join in any of the queries which you execute. ...
Running vs. Waiting: why are queries slow? If you find queries that exceed your predefined threshold, examine why they could be slow. The cause of performance problems can be grouped into two categories, running or waiting: WAITING: Queries can be slow because they're waiting on a bottleneck...