by Andrew Aksyonoff | Mar 27, 2007 | Insight for Developers
by Peter Zaitsev | Mar 27, 2007 | Insight for Developers
One may think changing PHP session handler from file based to database driven is fully transparent. In many cases it is, sometimes however it may cause some unexpected problems as happened to one of our customers. If you use file based sessions PHP will lock session...
by Peter Zaitsev | Mar 26, 2007 | Insight for Developers
Working with various projects using MySQL I observe a lot of problems are coming from very simple fact – product is designed containing features which developers do not know how to implement effectively. In many companies you would see “waterfall”...
by Peter Zaitsev | Mar 23, 2007 | Insight for DBAs
During last couple of months I had number of consulting projects with MySQL Query Cache being source of serious problems. One would see queries both for MyISAM and Innodb tables mysteriously stalling for few seconds with “NULL” in State column. These could...
by Peter Zaitsev | Mar 19, 2007 | Percona Events
I’ve already wrote we do not generally do a lot of on-site onsite consulting, but as I’m anyway going to be speaking at MySQL Users Conference anyway it may be good time for some onsite jobs. In fact I have already scheduled visits on Friday, Monday and...
by Peter Zaitsev | Mar 18, 2007 | Percona Events
Few days ago MySQL released MySQL 5.0.37 which I would call first real Community Version, because unlike previous versions which were released from the same source tree as Enterprise MySQL this one has some community features added, which is great. Also over last half...
by Peter Zaitsev | Mar 15, 2007 | Insight for DBAs
Reading last few days worth of planet MySQL and commenting on some entries as you can see. The post by Oli catches my attention. There is also PDF with more details available Oli is saying you can use MySQL with Active Active Clustering and MyISAM tables if you follow...
by Peter Zaitsev | Mar 15, 2007 | Insight for DBAs
Looking at post by Konstantin Osipov we should finally get Query Cache working with prepared statements in MySQL 5.1 The interesting thing Konstantin notes it just took few days to fix it – I believe MySQL Support Team alone spent much more times explaining...
by Peter Zaitsev | Mar 15, 2007 | Percona Events
We’d like to test few things in regards to MySQL and Innodb scalability with multiple CPUs but we seems to be short of boxes right now, all stuff we have access to is in production right now which makes it not good for benchmark. Could anyone lend us access to...
by Peter Zaitsev | Mar 13, 2007 | Insight for Developers
I get a lot of mail and I prefer to store it for long time if not forever. With modern hard disk sizes it should not be problem at all, but because of how mailing programs are written it causes a lot of problems. I’ve tried a lot of programs – Kmail,...
by Peter Zaitsev | Mar 7, 2007 | Insight for DBAs
Today I was cloning the master using LVM Snapshot and found it was taking quite a while to catch up, which highlighted replication could be the limiting factor for this system quite soon, so I decided to check what is limiting MySQL Replication speed. My first idea...
by Peter Zaitsev | Mar 6, 2007 | Insight for Developers
Last few days I had a lot of a lot of questions at MySQL Performance Forum as well as from our customers regarding query optimization… which had one thing in common – It is not query which needed to be optimized. Way too frequently people design schema...
by Peter Zaitsev | Mar 5, 2007 | Insight for DBAs
Where does real power of MySQL Storage Engines, and pluggable storage engines as MySQL 5.1 lays ? It is very much advertised this allows third parties to create their own storage engines and we can see solutions as Solid and PBXT . Plus there is Falcon storage engine...
by Peter Zaitsev | Feb 27, 2007 | Insight for Developers
Performance optimization is never ending story, you can virtually always find something else to optimize but while on generic system, not tuned by expert you often can get significant performance increase in the matter of hours further performance improvements become...
by Vadim Tkachenko | Feb 25, 2007 | Insight for DBAs
We often recommend to our clients to convert their current database from MyISAM tables to InnoDB. The transfer by itself in most cases is almost plain, however the application can be broken by new unexpected errors 1205 (ER_LOCK_WAIT_TIMEOUT) Lock wait timeout...
by Peter Zaitsev | Feb 20, 2007 | Percona Events
About half a year have passed since me and Vadim have left MySQL to do MySQL Consulting on our own. Bunch of people have been wondering about our experiences so I thought it would be worth to share it here. Feels Good. I always liked to be my own boss and funny enough...
by Peter Zaitsev | Feb 19, 2007 | Insight for Developers
In MySQL 5.0 mainly error control was improved, such as strict mode was added to change famous MySQL behavior of cutting too large strings, too big numbers and allowing you to use dates such as February 31st. In one case however reverse change was done – in...
by Peter Zaitsev | Feb 16, 2007 | Insight for Developers
One interesting problem with MySQL Optimizer I frequently run into is making poor decision when it comes to choosing between using index for ORDER BY or using index for restriction. Consider we’re running web site which sell goods, goods may be from different...
by Peter Zaitsev | Feb 14, 2007 | Insight for DBAs
I was working with customer today which has MySQL on a system with some 64GB or RAM running MyISAM, so they set key_buffer_size to 16G… and every few days MySQL crashes. Why ? Because key_buffer_size over 4GB in size is not really supported (checked with latest...
by Peter Zaitsev | Feb 14, 2007 | Insight for Developers
MySQL Replication is asynchronous which causes problems if you would like to use MySQL Slave as it can contain stale data. It is true delay is often insignificant but in times of heavy load or in case you was running some heavy queries on the master which not take...
