July 30, 2014

Traffic Tricks by Hosting Providers.

I already wrote once about hosting troubles which we had with this site a while back. Today we had another trouble to one of the European hit servers for ClickAider project. We had purchased this 1and1 server few months ago, before we were running into troubles and as it was running well and because we […]

MySQL Performance – eliminating ORDER BY function

One of the first rules you would learn about MySQL Performance Optimization is to avoid using functions when comparing constants or order by. Ie use indexed_col=N is good. function(indexed_col)=N is bad because MySQL Typically will be unable to use index on the column even if function is very simple such as arithmetic operation. Same can […]

MySQL Northern European Customer Conference

Yesterday I’ve attended MySQL Customers Conference in London. This event is much smaller size than Users Conference (one day and about 170 people attending) and surely less geeky – there were no one from MySQL Development Support or Consulting teams and Sales Engineers were as close as you could get. Though Anders Karlsson and Ivan […]

Be careful when joining on CONCAT

The other day I had a case with an awful performance of a rather simple join. It was a join on tb1.vid = CONCAT(‘prefix-’, tb2.id) with tb1.vid – indexed varchar(100) and tb2.id – int(11) column. No matter what I did – forced it to use key, forced a different join order, it did not want […]

Managing Slave Lag with MySQL Replication

The question I often get is how far MySQL may fall behind and how to keep replication from lagging. The lag you will see will vary a lot from application to the application and from load to load. Plus what is the most important within same application the lag will likely have spikes – most […]

MyISAM Scalability and Innodb, Falcon Benchmarks

We many times wrote about InnoDB scalability problems, this time We are faced with one for MyISAM tables. We saw that several times in synthetic benchmarks but never in production, that’s why we did not escalate MyISAM scalability question. This time working on the customer system we figured out that box with 1 CPU Core […]

Add an option to Fail on Innodb Initialize failure, Please ?

I already wrote about this issue but as I is third team I’m helping customers to resolve this “frm corruption” issue it is the time to return to it again. During MySQL 5.0 release cycle the change was made so now MySQL does not stop if Innodb storage engine failed to initialize but starts properly… […]

HighLoad 2007 Review

Almost two weeks have passed since HighLoad 2007 conference in Moscow, Russia so I’m pretty late with feedback and my only excuse I was pretty busy to spare some time for it. Lets start with bright side. The conference had a lot of great sessions by experts in their field. A lot of top Russian […]

UNION vs UNION ALL Performance

When I was comparing performance of UNION vs MySQL 5.0 index merge algorithm Sinisa pointed out I should be using UNION ALL instead of simple UNION in my benchmarks, and he was right. Numbers would be different but it should not change general point of having optimization of moving LIMIT inside of union clause being […]

What did we want Interns to do

About one month ago we posted a call for interns to work with us on various MySQL Performance related things. We got good number of replies and a lot of people wondered what tasks exactly we could offer as surely this sort of involvement should be fun and should teach you something.