July 24, 2014

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 my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also […]

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 this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions […]

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 ! Heikki Tuuri, Creator of Innodb will answer your Questions about Innodb at MySQL Performance Blog. Please leave your questions as […]

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 no locks to be held by the transaction, but I was wrong. Let’s take a look at this table and […]

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 Innodb will keep open while working in innodb_file_per_table mode. Unlike MyISAM Innodb does not have to keep open file descriptor […]

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 caches is to get them as large as you can if you have enough resources (such as memory). With MySQL […]

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 this interview was inspired by a previous interview with Heikki Tuuri – creator of InnoDB. You can see the answers […]

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 derived from estimates, and I know a decent amount about that. The interesting thing I wanted to look into was […]

Interested to learn about New Innodb Plugin Performance ?

As you probably have already heard Innodb Announced new Plugin version for MySQL 5.1 So now you can see Heikki and the Team were not just doing only bug fixes for last two years, but rather kept very quite. We had access to this code for few weeks and should say we were impressed in […]