…query in the right way. But vanilla MySQL…query_time=0, because if you set it to some other value say 0.1 seconds, it will miss all queries…count(*) from auto_inc; Note that logging all queries in this fashion as opposed to the general query…INSERT …per every query), interesting here is that this query…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…Per second averages calculated from the last 44 seconds Make sure data is sampled for at least 20-30 seconds…. The second piece of information is event counters – “reservation count” and “signal count” … entries 1 MySQL thread id 9697561, query id 188161264 localhost root update insert into child…
Post: How expensive is a WHERE clause in MySQL?
October 31, 2008 By 16 Comments
… CHARSET=latin1; insert into t(a) values(current_date); insert into t select…seconds, ranging from 4.83 to 5.17 seconds. Next I ran it with a trivial WHERE clause: mysql> select count…per row, but it adds up to about an extra 60% cost for the query. If I add another WHERE clause, mysql> select count…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
… a bit with INSERT … SELECT I decided to check is Innodb locks …per locked row; Now lets see how much exclusinve locks take: mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql> select count… 2.5 seconds on this pretty old box, which means locking speed will be few millions per second on…
Post: The perils of InnoDB with Debian and startup scripts
January 28, 2009 By 13 Comments
… | Sending data | insert into tableB… | 6322 | user | update | insert into | 6327 | user …Per second averages calculated from the last 15 seconds ———- SEMAPHORES ———- OS WAIT ARRAY INFO: reservation count 39125236, signal count…mysql tables in use 7, locked 0 MySQL thread id 6424, query…
Post: Just do the math!
July 6, 2009 By 4 Comments
…seconds. So what math would be in the case like this ? Say you have query like “SELECT page,count…MySQL may execute query above but lest focus on the most typical one – scan the table, when for each row insert… rows query can process per second in total. Lets assume it is 100K rows per second when …
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
…MySQL…inserts (multiple value inserts). Really helps if you have really bulk inserts 100-1000+ values per single insert statement. concurrent_insert – Enables concurrent insert…query log or general log. flush, flush_time Flushing (closing) of tables after query is complete or every flush_time seconds…
