I’m looking forward to Wednesday’s joint webinar on MySQL clustering technologies with Matt Aslett, research director of data management and analytics over at 451 Research. We’ll be participating in a live, in-depth discussion of MySQL Clustering for High Availability and Scalability. Matt will present an overview of the trends driving adoption of clustering technology. He’ll […]
Next Wednesday, Severalnines CTO Johan Andersson and I will co-present a webinar about ClusterControl, a cluster management tool created by Severalnines that can monitor Percona XtraDB Cluster. It provides DBAs with the right metrics to manage and optimize applications during development and production. In the webinar, titled “Performance Monitoring and Troubleshooting of Percona XtraDB Cluster,” we […]
MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I will show the results of executing benchmarks […]
I’ve heard this question a lot, but never thought to blog about the answer. “Is there a performance difference between putting the JOIN conditions in the ON clause or the WHERE clause in MySQL?” No, there’s no difference. The following queries are algebraically equivalent inside MySQL and will have the same execution plan.
SELECT * FROM A, B WHERE A.ID = B.ID;
SELECT * FROM A JOIN B ON A.ID = B.ID;
SELECT * FROM A JOIN B USING(ID);
…any sessions this year; Peter, Vadim, and the rest of us at Percona submitted over a dozen session proposals, which were initially declined. As …Cabral is organizing.
That’s the back story — now on to the Percona Performance Conference! This is not “another MySQL conference.” It’s a performance…to Santa Clara.
We will not be the only ones speaking at Percona Performance Conference; other experts will join us in making presentations too. …to propose a session, please do so through the Percona Performance Conference website.
The Percona team looks forward to greeting you face to face …
I start to see applications being built utilizing VIEWs functionality which appeared in MySQL 5.0 and quite frequently VIEWs are used to help in writing the queries – to keep queries simple without really thinking how it affects server performance. Even worse than that – looking at the short table which just gets single row […]
I prefer to use Integers for joins whenever possible and today I worked with client which used character keys, in my opinion without a big need. I told them this is suboptimal but was challenged with rightful question about the difference. I did not know so I decided to benchmark. The results below are for […]
In many Search/Browse applications you would see main (fact) table which contains search fields and dimension tables which contain more information about facts and which need to be joined to get query result. If you’re executing count(*) queries for such result sets MySQL will perform the join even if you use LEFT JOIN so it […]
In my last post, “A closer look at the MySQL ibdata1 disk space issue and big tables,” I looked at the growing ibdata1 problem under the perspective of having big tables residing inside the so-called shared tablespace. In the particular case that motivated that post, we had a customer running out of disk space in his […]