因为是等待MDL锁,所以先看看performance_schema.metadata_locks表,记录的顺序代表持有锁的时间顺序 select * from performance_schema.metadata_locks where OWNER_THREAD_ID!=sys.ps_thread_id(connection_id()); 1. 如下就是MDL相关的锁模式,以及对应的SQL语句 从图上可知,LOCK_TYPE 为SHARED_READ_ONLY的12606 ...
performance_schema_max_sql_text_length=1024 控制存入events_statements_current,events_statements_history和events_statements_history_long语句事件表中的SQL_TEXT列的最大SQL长度字节数。 超出系统变量performance_schema_max_sql_text_length的部分将被丢弃,不会记录,一般情况下不需要调整该参数,除非被截断的部分与其...
今天的学习内容是:SQL进阶-查询优化- performance_schema系列实战四:查看最近的SQL执行信息 一、 查看最近的top sql 我们优化慢SQL的思路:优先优化执行次数最多的,然后是执行时间最长的。 可以使用events_statements_summary_by_digest表来查询经过统计之后的top sql 1.1 数据准备(如果已有数据可跳过此操作) 使用sysbenc...
Comma separated list of attribute names this allows to return only a subset of SQL attributes: EXECUTION_STATISTICS, BIND_LIST, OBJECT_LIST, SQL_PLAN,SQL_PLAN_STATISTICS: similar to SQL_PLAN + row source statistics ***/ ---7.查询sql优化集 select sql_id,sql_text from dba_sqlset_statements...
View Code #EXPANSIVE QUERIES View Code #Table in buffer View Code #Indexes Ananize View Code #DB growth rate View Code #Index use frequncy View Code #sp_msforeachdb View Code https://blog.sqlauthority.com/2019/06/14/sql-server-clean-pages-and-dirty-pages-count-memory-buffer-pools/ ...
The PartialFinal policy is suitable for scenarios in which the aggregation performance cannot meet your requirements when you use the COUNT DISTINCT function. Important You cannot enable PartialFinal in the Flink SQL code that contains user-defined aggregate functions (UDAFs). To prevent resources...
Every layer of the stack affects performance; storage, virtualisation, database and application. Learn more about how Pure, VMware and SQL Server can be tuned to make your application run faster. Learn About SQL Server High Availability Database Workloads at Massive Scale Face data gravity issu...
Improve Your VMware SQL Server High Availability Environment Every layer of the stack affects performance; storage, virtualisation, database and application. Learn more about how Pure, VMware and SQL Server can be tuned to make your application run faster. ...
·CPU performance counters ·SQL Server blocking related performance counters ·Network performance counters ·Defining your own counters ·Advanced Performance Analysis; ·The USE method 概括一下,就是请求到受理,受理到执行,执行到结果,结果到展现。 每部分都会有些等待,弄清楚这些等待,就知道为什么请求处理得...
打开Enterprise Manager Database Control 并单击 Performance 选项卡。然后滚动到页面底部,您将看到如下超链接。 单击Search Sessions,出现如下屏幕: 从游标缓存中搜索已经执行的 SQL 中的模式。注意,这些 SQL 都有一个注释 CONTROL_QUERYn,其中 n 为 11、12 等等。输入该字符串作为搜索函数。将给出先前执行过的所...