… specify slow query time in microseconds rather than seconds and allows you to log all queries in slow query log by setting long_query_time=0 This… log for all your queries with long_query_time=0 so if serious portion of you load comes from very simple queries you would not… time. Happily you can change long_query_time without restarting server so it is easy to get sample of all queries for some period of time…
Post: Get Me Some Query Logs!
November 22, 2012 By 14 Comments
… Discovering slow_query_log=1 Discovering slow_query_log_file=mysql-slow.log Discovering long_query_time=60.000000 Setting long_query_time=0 Setting slow_query_log_file=mysql-slow.log-full-20121122112413 Setting slow_query_log=1 Flushing slow query…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… have enabled slow query logging and set a low enough value for long_query_time. We normally use a value of long_query_time=0, because if you set it to some other value say 0.1 seconds, it will miss all queries shorter… where this query was executed. Next the “Query_time distribution” section shows how this query times mostly, which you can see majority of the time lies…
Post: Optimizing slow web pages with mk-query-digest
April 7, 2011 By 14 Comments
… – I had a slow query log (captured with long_query_time=0 and all the eXtra benefits from Percona slow query log patch), I knew… top slowest queries, I asked it to list me top slowest sessions: mk-query-digest –group-by=Thread_id –order-by=Query_time:sum… all the other useful information, not even query timing. Instead, I’ve used mk-query-digest: mk-query-digest –filter=’$event->{Thread_id} == 160847…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
… which was to treat long_query_time value as seconds. In effect one could only choose to log all queries to see those which take less than 1s. Now long_query_time is in microseconds and you can set it for example to 300000 which is 0.3s! # Query_time: 0.503016 Lock_time…
Post: Poor man's query logging
November 7, 2008 By 5 Comments
… –log-slow-queries parameter (MySQL 5.1 requires also –slow-query-log), which was designed to store poorly performing queries that run at… the slow log to, among others, include any query regardless of the execution time. The problem is that for both you need… simply setting long_query_time MySQL variable vale high enough). So what can be done when you really need to see the queries, but…
Post: Enabling/Disabling query log without server restart in MySQL 5.0
September 13, 2007 By 13 Comments
… this patch you can get all queries logged as slow queries (with times) and as you can change long-query-time online you can effectively enable and disable debug logging live. Note however this is not 100% equivalent for general query…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
… query to be logged it must match long_query_time AND min_examined_row_limit AND log_slow_filter. log-slow-queries[=name] Log slow queries… changed at run time with both SET SESSION and SET GLOBAL. long_query_time=# Log all queries that have taken more than long_query_time microseconds to execute…
Post: Microslow patch for 5.1.20
July 18, 2007 By 3 Comments
…-queries=slow.log and –log-output=FILE. Also you need to configure so called long query time. It’s done either with startup parameter –long_query_time=n or by setting MySQL system variable with SET [SESSION|GLOBAL] long_query_time=n…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… list of queries which load replication the most. It however works only with statement level replication. You need to set long_query_time=0 and log_slave_slow_statements=1 for this method to work. Get the log file which will include all queries MySQL server ran with their times and run mk-query-digest with filter to only check queries from replication thread: mk-query-digest…
