MySQL 5.6 has a great many new features, including, but certainly not limited to a number of performance improvements. However, besides the widely talked-about features such as InnoDB support for full text search, optimizer, performance schema improvements and GTID, there are also a few tiny improvements that nobody cared to mention. One such feature is…
Thanks to everyone who was in attendance on 05 June 2013 for my “Choosing a MySQL HA Solution” webinar. If you weren’t able to make it but are interested in listening to the presentation, it’s currently up and available for viewing over at percona.com. My apologies if we weren’t able to get to your question […]
As I stated in my last post, I decided to use the Innodb Table monitor to diagnose an Index count mismatch error a customers found in their mysqld.err log to verify if the problem still existed. The Innodb Table Monitor has existed for basically forever in Innodb (the MySQL manual discusses it back in the 4.1 […]
I recently worked on a customer case where at seemingly random times, inserts would fail with Innodb error 139. This is a rather simple problem, but due to it’s nature, it may only affect you after you already have a system running in production for a while.
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and […]
When I did NDB Cluster engagements, it happened a few time that I had to cover the NDB API. Once, a customer asked an example on how to perform a simple scan. Remembering that some examples are within the NDB source tree, under ./storage/ndb/ndbapi-examples/ and I decided to take a look, why writing something when […]
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
So lets say you have .frm file for the table and you need to recover CREATE TABLE statement for this table. In particular when we do Innodb Recovery we often get .frm files and some mess in the Innodb tablespace from which we have to get data from. Of course we could relay on old […]
Quite frequently I see customers looking at recovery as on ability to restore data from backup which can be far from being enough to restore the whole system to operating state, especially for complex systems. Instead of looking just at data restore process you better look at the whole process which is required to bring […]
Assume you’re running MySQL with Innodb tables and you’ve got crappy hardware, driver bug, kernel bug, unlucky power failure or some rare MySQL bug and some pages in Innodb tablespace got corrupted. In such cases Innodb will typically print something like this: InnoDB: Database page corruption on disk or a failed InnoDB: file read of […]