Emergency

Search Results for: heikki

Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide …


Heikki Tuuri Innodb answers – Part I

Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about …


Heikki Tuuri to answer your in depth Innodb questions

Have you ever had a question about Innodb internal design or behavior which is not well covered in MySQL manual ? I surely had. Now you have a great chance to have them answered ! …


Is 80% of RAM how you should tune your innodb_buffer_pool_size?

It seems these days if anyone knows anything about tuning InnoDB, it’s that you MUST tune your innodb_buffer_pool_size to 80% of your physical memory. This is such prolific tuning advice, it seems engrained in many …


One more InnoDB gap lock to avoid

While troubleshooting deadlocks for a customer, I came around an interesting situation involving InnoDB gap locks. For a non-INSERT write operation where the WHERE clause does not match any row, I expected there should’ve been …


Percona turns 5 years old

It’s August 1st, 2011, and five years ago on or about this date (who can remember clearly?) Peter Zaitsev and Vadim Tkachenko founded Percona. What’s happened in the last five years?


How innodb_open_files affects performance

Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to look at yet another similar variable – innodb_open_files which defines how many files …


table_cache negative scalability

Couple of months ago there was a post by FreshBooks on getting great performance improvements by lowering table_cache variable. So I decided to investigate what is really happening here. The “common sense” approach to tuning …


Would you like to ask a question about PBXT?

In the next week, I’ll be interviewing Paul McCullagh, the architect behind the PBXT storage engine. If you have any questions for Paul, please post them here by Monday 16th November. Note: The idea for …


Why InnoDB index cardinality varies strangely

This is a very old draft, from early 2007 in fact. At that time I started to look into something interesting with the index cardinality statistics reported by InnoDB tables. The cardinality varies because it’s …