Here is a select query which executes in 0.03 sec: select * from engine.transactions where transaction_row not in (select transaction_row from d.pos_transactions) I want to update the matched (selected) rows from the query above this way: You must ensure that the variable slow_query_log is set to ON, while the slow_query_log_file determines the path where you need to place your slow query logs. If this variable is not set, it will use the DATA_DIR of your MySQL data directory.. MySQL delete is very slow and takes long time! Use timeouts to prevent long-running SELECT queries from taking down your MySQL. MySQL Forums Forum List » Newbie. The refresh time is strictly related to what your query does, and the measures you wrote. Advanced Search. Navigate: Previous Message• Next Message. The query that now generates most slow queries is the following (see result from mysqldumpslow): Count: 433 Time=3.40s (1470s) Lock=0.00s (0s) Rows=0.0 (0), UPDATE user_sessions SET tid='S' WHERE idsession='S' I am very surprised to have so many long queries for such a simple query with no locking. SQL update satement taking a very long time / high disk usage for hours. Rick James. Re: A simple update query taking long time. Options: Reply• … New Topic. Posted by: Muntaquim Bagadia Date: December 05, 2013 09:48PM There are other MyISAM tables in the database - wouldn't query cache help in performance of those tables? Advanced Search. MySQL has a built-in slow query log. To use it, open the my.cnf file and set the slow_query_log variable to "On." (google sheets in your case). I've looked at other answers on here and all of them take a very long time as well. The slow query log can be used to find queries that take a long time to execute … Keep in mind, the lower your long_query_time directive the faster the slow query log fills up a disk partition Fyi, the table is InnoDB and has 14000 rows. Accompanied by the slow_query_log variable are the long_query_time and min_examined_row_limit which impacts how the slow query … Unlike excel version, you cannot bring data directly in Power Pivot, so you have a query from a website. In addition the PHP max_execution_time does not apply to waiting for network calls as shown in this previous blog post on max_execution_time. Re: A simple update query taking long time. MySQL Forums Forum List » Newbie. New Topic. Any help would be appreciated, thanks. Posted by: Rick James ... A simple update query taking long time. Re: A simple update query taking long time. Navigate: Previous Message• Next Message. in Linux/Unix by Prabhu Balakrishnan on February 7, 2011 I recently had an issue with mysql database and the database has grown too large about 200k records and i was needing to delete all junk and needless data of approx 50k rows in my table. The slow query log consists of SQL statements that take more than long_query_time seconds to execute and require at least min_examined_row_limit rows to be examined. Advanced Search. The query I am using is: USE the_db; UPDATE table1 JOIN table2 ON table2.a = table1.b SET table1.c = "Y"; I've changed the names of the tables and columns, but the query is exactly the same. If the refresh time is slow, then the query is slow. Posted by: Muntaquim Bagadia Date: December 03, 2013 01:14AM No,nothing else was touching this - the load on the server was also normal during this time. MySQL Forums Forum List » Newbie. New Topic. PBI has power query and power pivot as modelling tools. There is a large disk space concern with the slow query log file, which needs to be attended to continually until the slow query log feature is disabled. Set slow_query_log_file to the path where you want to save the file. Muntaquim Bagadia. December 04, 2013 11:55PM Re: A simple update query taking long time. This is an Innodb table. Set long_query_time to the number of seconds that a query should take to be considered slow, say 0.2.