> -----Original Message----- > From: Vikas Shukla [mailto:myfriendvi...@gmail.com] > Sent: Thursday, May 30, 2013 7:19 PM > To: Robinson, Eric; mysql@lists.mysql.com > Subject: RE: Are There Slow Queries that Don't Show in the > Slow Query Logs? > > Hi, > > No, it does not represents the time from request to response > not does it includes the time that is spent in waiting for > the locks to be released. > The slow query log consists of SQL statements that took more > than long_query_time seconds to EXECUTE. The default value of > long_query_time is 10. > The time to acquire the initial locks is not counted as > execution time. > mysqld writes a statement to the slow query log after it has > been executed and after all locks have been released, so log > order might differ from execution order. > > Lets take an example, if a query is received at 10:00 hrs and > it waits till 10:05 hrs , it starts getting executed at > 10:05:00 and completed at 10:05:24 (HH:MM:SS). So, here it > took 24 seconds to execute. So only > 24 seconds is counted. > So if long_query_time is equal to 10, which is by default, > this would be logged in slow query log as it takes more than > 10 seconds to execute. > > Sent from my Windows Phone From: Robinson, Eric > Sent: 31-05-2013 03:48 > To: mysql@lists.mysql.com > Subject: Are There Slow Queries that Don't Show in the Slow > Query Logs? > As everyone knows, with MyISAM, queries and inserts can lock > tables and force other queries to wait in a queue. When that > happens, does the time shown in the slow query logs represent > the whole time from when the server received the request to > when the response was sent to the client? Or is the time a > query spends waiting for a table lock to be released omitted > from what is recorded in the slow query logs? > > -- > Eric Robinson > >
Very good answer, Vikas. Thank you for the clarification! --Eric Disclaimer - May 31, 2013 This email and any files transmitted with it are confidential and intended solely for Vikas Shukla,mysql@lists.mysql.com. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physicians' Managed Care or Physician Select Management. Warning: Although Physicians' Managed Care or Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. This disclaimer was added by Policy Patrol: http://www.policypatrol.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
