Category Archives: videos

Why does the MySQL optimizer not do what I think it should?

In May, I presented two talks – one called “Are you getting the best out of your indexes?” and “Optimizing Queries Using EXPLAIN”. I now have slides and video for both of them.

The first talk about indexing should probably be titled “Why is MySQL doing this?!!?!!?” It gives insight into why the MySQL optimizer chooses indexes that you do not expect; especially when it does not use an index you expect it to.

The talk has something for everyone – for beginners it explains B-trees and how they work, and for the more seasoned DBA it explains concepts like average value group size, and how the optimizer uses those concepts applied to metadata to make decisions.

Slides are at http://technocation.org/files/doc/2017_05_MySQLindexes.pdf.
Click the slide image below to go to the video at https://www.youtube.com/watch?v=e39-UfxQCCsSlide from MySQL indexing talk

The EXPLAIN talk goes through everything in EXPLAIN – both the regular and JSON formats – and describes what the fields mean, and how you can use them to figure out how to best optimize your query. There are examples that show where you can find red flags, so that when you EXPLAIN your own queries, you can be better prepared for gotchas. The EXPLAIN talk references the indexing talk in a few places (both talks were given to the same audience, about a week apart), so I highly recommend you watch that one first.

Slides are at .
Click the slide image below to go to the video at https://www.youtube.com/watch?v=OlclCoWXplgSlide image from the EXPLAIN talk

2013 SkySQL and MariaDB Solutions Videos Are Online!

I do not recall seeing an announcement about it, but I went looking for the videos today and lo and behold, they were up! Forgive me if I missed a post about it. But if you also missed it, here they are:

2013 SkySQL and MariaDB Solutions Day for the MySQL Database videos

MySQL User Group Video – Determinism and Databases

The May Boston MySQL User Group featured John Hugg of VoltDB talking about determinism and databases. I have uploaded the hour-long video to http://www.youtube.com/watch?v=mTDLyRauJtw. Seasoned MySQLers will nod their heads because the problems described are familiar, and those who are not exactly sure what determinism and databases means will learn a lot.

Enjoy!

(As always, videos are free on YouTube with no login or attempt to solicit your e-mail address or any other information)

Videos from Open Database Camp

Open Database Camp was just over a week ago, Mar 16-17th at Harvard University, co-located with Northeast LinuxFest. We had a great lineup of speakers, and we have processed all 11 videos in record time! We got new video cameras at the beginning of the year, so the video quality and resolution is stellar, you can see everything. Here are the videos:

2013 Open Database Camp
and Related Northeast LinuxFest Videos

  • Fractal Tree Indexes by Tim Callaghan of Tokutek
    (45:23)
  • Elastic Database Virtualization by Amrith Kumar of ParElasticy
    (56:25)
  • Elastic Clustering with Serializable Isolation by Ariel Weisberg of VoltDB
    (27:23)
  • MariaDB: An introduction to 10 What Weve Achieved by Colin Charles of Monty Program
    (38:37)
  • Introduction to MongoDB by H. Waldo Grunenwald
    (47:08)
  • MySQL and MariaDB: Past, Present and Future by Max Mether of SkySQL
    (47:38)
  • MySQL 5.6 Replication features and usability by Giuseppe Maxia of Continuent
    (51:02)
  • Congratulations! Youre the New Linux Admin and the MySQL DBA by Dave Stokes of Oracle
    (36:44)
  • High Availability Solutions for MySQL by Max Mether of SkySQL
    (39:41)
  • Creating Multi-master Clusters with Tungsten Replicator by Giuseppe Maxia of Continuent
    (63:35)
  • MySQL Backups by Sheeri Cabral of Mozilla
    (56:48)

Enjoy!