If this function returns true, explain_into_variable_name() returns the name of the variable. Return values trueEXPLAIN output should be stored in a user variable. falseEXPLAIN output should be sent to the client. virtual bool Explain_format::is_hierarchical()const ...
These rules are useful when you are not sure of the port or other required settings, because you only specify the path to the program’s executable (.exe) file. Port rules. These control connections for a TCP or UDP port. Use this type of firewall rule to allow a co...
可以通过两种方式定位执行效率较低SQL语句: 使用参数:--log-slow-queries [=file_name],MySQL会将long_query_time的SQL语句日志写入文件; 使用参数show processlist:查询MySQL线程状态、是否锁表。 慢查询日志在查询结束以后才记录,在应用反映执行效率问题时查询慢查询慢查询日志并不能定位问题。可以使用show processlist...
要动态准备并说明的 SQL 或 XQuery 查询语句。要说明多个语句,请使用-stmtfile选项提供一个文件(其中包含所要说明的查询语句),或使用-terminator选项来定义可用来分隔-statement选项中的语句的终止字符。 -stmtfilequery-statement-file 指定一个文件,其中包含一个或多个要动态准备并说明的查询语句。缺省情况下,假定该...
How to explain the code below in the loop so I... Learn more about for loop, csv, faq, process a sequence of files
slow_query_log =1log_queries_not_using_indexes =1long_query_time =0.1slow_query_log_file = c:\mysql\log\mysqlslowquery.log 我在配置文件中设置了。所以我重启让配置生效。 ps:slow_query_log_file这个路径要有效且有权限,否则重启后无法写入log ...
Describe the pathway of oocytes. Describe the pathway of sperm. Explain the adaptation of the small intestine to their functions. Explain the process of absorption through the nephron of the kidney. Include what is absorbed, where, and types of tissue cells ...
"bloom filters in the LSM tree":0,"chunks in the LSM tree":0,"highest merge generation in the LSM tree":0,"queries that could have benefited from a Bloom filter that did not exist":0,"sleep for LSM checkpoint throttle":0,"sleep for LSM merge throttle":0,"total size of bloom ...
In cases where there is an alternative plan that performed better than the plan generated by the optimizer, the first step in diagnosing why the Optimizer picked the sub-optimal plan is to visually inspect both of the execution plans. Examining the different aspects of an execution plan, from ...
db2look -d DB_NAME -a -e -m -l -f -o filename.sql 1. 如何恢复数据库 restore db db1 to /tstdb2/catalog into db newlogpath /tstdb2/db2log buffer 2048 replace existing redirect parallelism 16; set tablespace containers for 1 using (path '/tstdb2/db2tmp'); set tablespace containers...