php - A website running online, how to check whether which sql statement needs optimization?

Question

For example, if a website is running online and it is found that a certain page loads very slowly, how to check whether which SQL statement needs to be optimized

Answer 1

Slow query log.

Answer 2

Check the log and find the corresponding sql desc or explain select....(your sql statement) to check the efficiency, or write the execution efficiency directly to the log

Answer 3

If it is Laravel, you can use debugbar https://github.com/barryvdh/l...

Answer 4

In the configuration of mysql, enable slow query slow_query_log and statement without index log_queries_not_using_indexes. You can use the explain + sql statement to check the execution efficiency of sql.

You should also pay attention to whether it can be optimized in the program. Don't put database queries in loops.

Answer 5

Have you used a framework? You can monitor the running time of each SQL. And record the logs and analyze them one by one.