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 was to check it based on slow […]
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 first and then think how the queries […]
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 being […]Read more
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 more and more time consuming and expensive and gains smaller.
This observation […]
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
Lock wait timeout expired. Transaction was rolled back.
Transaction deadlock. You should rerun the transaction.
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 regards to storage engine […]
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 categories, different sellers different locations which can be filtered on, and […]
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 and greatest MySQL Enterprise 5.0.34). […]