October 21, 2014

check-unused-keys: A tool to interact with INDEX_STATISTICS

With the growing adoption of Google’s User Statistics Patch**, the need for supporting scripts has become clear. To that end, we’ve created check-unused-keys, a Perl script to provide a nicer interface than directly querying the INFORMATION_SCHEMA database.

Getting MySQL to use full key length

There is one bug, or “missing feature” in MySQL Optimizer which may give you hard time causing performance problems which may be hard to track down, it is using only part of the index when full index can be used or using shorter index while there is longer index available. The last item is yet […]

OpenStack users shed light on Percona XtraDB Cluster deadlock issues

I was fortunate to attend an Ops discussion about databases at the OpenStack Summit Atlanta this past May as one of the panelists. The discussion was about deadlock issues OpenStack operators see with Percona XtraDB Cluster (of course this is applicable to any Galera-based solution). I asked to describe what they are seeing, and as […]

Q&A: Putting MySQL Fabric to use

Martin Arrieta and I gave an online presentation last week on “Putting MySQL Fabric To Use.” If you missed it, you can find a recording and the slides here, and the vagrant environment we used plus a transcript of the commands we ran here (be sure to check out the ‘sharding’ branch, as that’s what we used […]

Advisory on Heartbleed (CVE-2014-0160) for Percona’s customers and users

Over the last few days, the Percona team has spent a lot of time evaluating the impact of the Heartbleed bug (CVE-2014-0160) for our customers and for the users of our software. We published a formal disclosure a few days ago. However, I thought a quick summary and some additional information would be good to […]

Keynote Speakers for Percona Live MySQL Conference 2014 and $5 Expo Only Passes

The Percona Live MySQL Conference 2014 in Santa Clara, California is just around the corner: April 1-4. There is a tremendous amount of activity leading up to the conference, some of which I will highlight here. Percona Live MySQL Conference 2014 Keynote Speakers I am extremely pleased with the keynote speakers we can now announce. […]

Useful MySQL 5.6 features you get for free in PXC 5.6

I get a lot of questions about Percona XtraDB Cluster 5.6 (PXC 5.6), specifically about whether such and such MySQL 5.6 Community Edition feature is in PXC 5.6.  The short answer is: yes, all features in community MySQL 5.6 are in Percona Server 5.6 and, in turn, are in PXC 5.6.  Whether or not the new […]

InnoDB scalability issues due to tables without primary keys

Each day there is probably work done to improve performance of the InnoDB storage engine and remove bottlenecks and scalability issues. Hence there was another one I wanted to highlight: Scalability issues due to tables without primary keys This scalability issue is caused by the usage of tables without primary keys. This issue typically shows […]

Want to archive tables? Use Percona Toolkit’s pt-archiver

Percona Toolkit’s pt-archiver is one of the best utilities to archive the records from large tables to another tables or files. One interesting thing is that pt-archiver is a read-write tool. It deletes data from the source by default, so after archiving you don’t need to delete it separately. As it is done by default, you […]

When it’s faster to use SQL in MySQL NDB Cluster over memcache API

Memcache access for MySQL Cluster (or NDBCluster) provides faster access to the data because it avoids the SQL parsing overhead for simple lookups – which is a great feature. But what happens if I try to get multiple records via memcache API (multi-GET) and via SQL (SELECT with IN())? I’ve encountered this a few times […]