sql sleep

Know that you can have this statement run for n seconds by executing select sleep (n) in MySQL:[SQL]View PlainCopy  Mysql> Select Sleep (1); +----------+   | Sleep (1) | +----------+   | 0 | +----------+   1 row in

Know that you can have this statement run for n seconds by executing select sleep (n) in MySQL:Mysql> Select Sleep (1); +----------+| Sleep (1) |+----------+| 0 |+----------+1 row in Set (1.00 sec)The execution time returned to the client

Know that you can have this statement run for n seconds by executing select sleep (n) in MySQL:? 1234567 mysql> selectsleep(1);+----------+| sleep(1) |+----------+|        0 |+----------+1 row in set(1.00 sec) The

All know that by executing select sleep (n) in MySQL, you can have this statement run for N seconds: Mysql> Select Sleep (1);+----------+| Sleep (1) |+----------+| 0 |+----------+1 row in Set (1.00 sec) The execution time returned to the client

Run show processlist in mysql. There are many such processes in the database:In fact, there are too many Sleep connections in MySQL, so there are three reasons for the sleep:1. Before the client program exits, it does not call mysql_close (). [write

Use sleep in PHP to cause MySQL read failure cases and workarounds, Sleepmysql Recently, due to project demandThe sleep function is needed to periodically fetch a heap of data from the database to perform certain operations.Sleep waits at least one

The perfect solution for too many MySQL sleep connections is too many sleep connections. What will happen to the mysql server? It seriously consumes mysql Server resources (mainly cpu and memory) and may cause mysql to crash. What causes excessive

Query the current number of connections in MySQL:Mysql> Show status like '%threads_connected% '; +-------------------+-------+| Variable_name | Value |+-------------------+-------+| threads_connected | +-------------------+-------+1 row in

There have been similar problems before, the cause of this problem from the Internet to check, there are several reasons: Cause of excessive sleep connections? 1. Too many persistent connections used (personally, it is not appropriate to use a

PHP's garbage collection mechanism, in fact, is only for PHP itself.For mysql,php, there is no right to automatically release its things.If you do not call Mysql_close () before the page finishes executing, the connection will not be closed by MySQL.