…What cache hit rate is good for optimal MySQL Performance” is typical question I’m asked. It could by MyISAM key_buffer…/sec and you see Innodb_data_reads incremented by 10 per second (mysqladmin extended -i10 -r is your friend in computing this… is it is unlikely the problem for MySQL Performance. If it is however 120 per second it well could be. It is still…
Post: Edge-case behavior of INSERT...ODKU
October 27, 2012 By 6 Comments
… a rate of approximately 1500 to 2000 per second, sustained, 24h per day. The mathematically-astute among you may…to be considered as being defined first. So, MySQL checks our INSERT, sees that the next auto… you might think; the original customer table in question had less than 500K rows in it. Using…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions…same case. Some people would prefer to define second key as UNIQUE this has benefits and … you can have, which is 64 per table in recent MySQL versions. However it is often …
Post: Tools and Techniques for Index Design Webinar Questions Followup
October 4, 2012 By 5 Comments
…I got a number of good questions. Here are the questions (paraphrased), with my answers. …current versions of MySQL. Q: How do the upcoming changes in MySQL 5.6…Is it always the case that no second-star index exists for a query…predicate, add columns to avoid sorting per query, and add further columns …
Post: How fast can MySQL Process Data
April 9, 2008 By 3 Comments
… data processing limitations of current systems. This raises valid question how fast can MySQL process (filter) data using it current architecture ? I… rows per second it will be able to do? CREATE TABLE `m` ( `i` int(11) NOT NULL ) ENGINE=MEMORY DEFAULT CHARSET=latin1 mysql… a bit longer rows we instantly get 4.3M rows per second. And now if we look at the memory amount consumed…
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
…. Virtualization however adds yet another layer and we need to question again whenever IO really durable in virtualized environments. My simple… to do no more than a bit over 100 writes per second as even in case there is no disk seek we… it times only writes not fsync() calls…. 22 fsync requests per second is pretty bad though I assume It can be realistic…
Comment: Why do you need many apache children ?
February 17, 2008 By 15 Comments
Moreover I have one question on optimal concurrent mysql connection in active state. If all the queries required in …, it takes only 0.005 seconds or so. If so 100 concurrent mysql connections per second can handle 20000 queries per second. Front end queries does not include complex group by or extra file sorting at all. Of course, the optimal concurrent mysql…
Post: Is your server's performance about to degrade?
May 18, 2010 By 13 Comments
…I’m seeing this in servers running 20k queries per second and higher, lots of memory, lots of CPU … half a second? This is not a hypothetical question. If your server freezes routinely for half a second, then…it — and that’s where improvements to the MySQL source code are necessary. But in many cases…
Post: MySQL on Amazon RDS part 2: Determining Peak Throughput
March 28, 2011 By 4 Comments
…, I ran a series of 60-second benchmarks on the RDS server, and extracted the transactions per second from them, then used the… benchmark runs. Now, you may ask the question, is a duration of 60 seconds a good way to decide on a number… choosing a good benchmark length. The answer is no, 60 seconds is not enough to decide. However, while testing a variety…
Post: mysql-proxy, urgh performance and scalability ?
June 9, 2009 By 44 Comments
… proxy solution, and mysql-proxy is one of well-known, so it was logical first choice. The obvious question which come in mind is what performance penalty we have using mysql-proxy, version 0.7… connections, here are results (in transactions per second, more is better) ThreadsMySQL-5.0.77MySQL-proxy+MySQL-5.0.77 1 660.02…
