I don’t use many tools in my consulting practice but for the ones I do, I try to know them as best as I can. I’ve been using mk-query-digest for almost as long as it exists but it continues to surprise me in ways I couldn’t imagine it would. This time I’d like to share [...]
Active Cache for MySQL
January 10, 2010 By 11 Comments
One of the problems I have with Memcache is this cache is passive, this means it only stores cached data. This means application using Memcache has to has to special logic to handle misses from the cache, being careful updating the cache – you may have multiple data modifications happening at the same time. Finally [...]
Few more ideas for InnoDB features
June 29, 2009 By 7 Comments
As you see MySQL is doing great in InnoDB performance improvements, so we decided to concentrate more on additional InnoDB features, which will make difference. Beside ideas I put before http://www.mysqlperformanceblog.com/2009/03/30/my-hot-list-for-next-innodb-features/ (and one of them – moving InnoDB tables between servers are currently under development), we have few mores: – Stick some InnoDB tables / [...]
Adjusting Innodb for Memory resident workload
March 25, 2009 By 11 Comments
As larger and larger amount of memory become common (512GB is something you can fit into relatively commodity server this day) many customers select to build their application so all or most of their database (frequently Innodb) fits into memory. If all tables fit in Innodb buffer pool the performance for reads will be quite [...]
High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work. The first thing these have in common is that they’re generally some kind of loggable event. The next characteristic of a lot of these systems (real or planned) is [...]
SHOW OPEN TABLES – what is in your table cache
December 14, 2008 By 3 Comments
One command, which few people realize exists is SHOW OPEN TABLES – it allows you to examine what tables do you have open right now: mysql> show open tables from test; +———-+——-+——–+————-+ | Database | Table | In_use | Name_locked | +———-+——-+——–+————-+ | test | a | 3 | 0 | +———-+——-+——–+————-+ 1 row in [...]
Thoughs on Innodb Incremental Backups
November 10, 2008 By 8 Comments
For normal Innodb “hot” backups we use LVM or other snapshot based technologies with pretty good success. However having incremental backups remain the problem. First why do you need incremental backups at all ? Why not just take the full backups daily. The answer is space – if you want to keep several generations to [...]
Living with backups
November 6, 2008 By 28 Comments
Everyone does backups. Usually it’s some nightly batch job that just dumps all MySQL tables into a text file or ordinarily copies the binary files from the data directory to a safe location. Obviously both ways involve much more complex operations than it would seem by my last sentence, but it is not important right [...]
Development plans
September 8, 2008 By 5 Comments
We gathered together our ideas of MySQL improvements on this page http://www.percona.com/percona-lab/dev-plan.html and we are going to implement some of them. My favorite one is – make InnoDB files .ibd (one created with –innodb-file-per-table=1) movable from one server to another, however it is sort of challenging. Probably next one patch we want to integrate is [...]
Missing Data – rows used to generate result set
July 20, 2008 By 15 Comments
As Baron writes it is not the number of rows returned by the query but number of rows accessed by the query will most likely be defining query performance. Of course not all row accessed are created equal (such as full table scan row accesses may be much faster than random index lookups row accesses [...]
