Where is the slow query log?
/var/lib/mysql/
By default, the slow query log file is located at /var/lib/mysql/hostname-slow. log.
How do I trace a mysql query?
How to show the queries log in MySQL?
- Enable Query logging on the database. SET global general_log = 1; SET global log_output = ‘table’;
- Now you can view the log by running this query: SELECT * FROM mysql. general_log;
- If you want to disable query logging on the database, run this query: SET global general_log = 0;
How do I find slow mysql queries?
To simplify examining the queries in a long slow query log, you can use mysqldumpslow command on some versions of MySQL. Queries that do not use indexes can also be logged in the slow query log by including the — log-queries-not-using-indexes option.
How do I see slow queries in mysql?
To enable the slow query log, type the following command at the mysql> prompt: SET GLOBAL slow_query_log = ‘ON’; There are additional options that you can set for the slow query log: By default, when the slow query log is enabled, it logs any query that takes longer than 10 seconds to run.
Why are queries written to the slow query log?
Queries are written to the slow query log after all locks have been released. This reduces the time locks are held, but means that two queries requiring the same table locks may end up in the slow query log in opposite order. The execution time measured for the query is the real-time (wall clock time) it takes to execute the query.
Why does my SQL query take so long?
You’ll query a view, which queries another view, which queries a table. This adds extra complexity and can slow down your query. Consider only accessing one view for your query. If you have multiple views for a query, where a view is querying another view, consider creating a new specialised view for it.
How is the query time measured in MySQL?
The query time is measured from after any initial table locks have been acquired. Queries are written to the slow query log after all locks have been released. This reduces the time locks are held, but means that two queries requiring the same table locks may end up in the slow query log in opposite order.
How to slow down a query in Excel?
Using functions in a Where clause or Join clause can also slow down your query. For example, if you filter on an uppercase word, then the value in every row needs to be converted to uppercase to do the conversion: