September 2, 2014

Adaptive checkpointing

Do you know that there are two limits about dirty (modified but not flushed to disk) blocks of InnoDB buffer pool? One is the limit of “amount”. The other is the limit of “age”. – limit of “amount” – As you know, buffer pool of InnoDB works as write-back cache of its datafiles. If the […]

JOIN Performance & Charsets

We have written before about the importance of using numeric types as keys, but maybe you’ve inherited a schema that you can’t change or have chosen string types as keys for a specific reason. Either way, the character sets used on joined columns can have a significant impact on the performance of your queries. Take […]

A common problem when optimizing COUNT()

When optimizing queries for customers, the first thing I do with a slow query is figure out what it’s trying to do. You can’t fully optimize a query unless you know how to consider alternative ways to write it, and you can’t do that unless you know what the query “means.” I frequently run into […]

The performance effects of new patches

We are going to show the effects of the new patches applied to Percona HighPerf release. As you see from the following graphs, there is significant difference to normal version when the data bigger than buffer pool (right graph shows CPU usage)

The ultimate tool for generating optimal my.cnf files for MySQL

There are quite a few “tuning primers” and “my.cnf generators” and “sample my.cnf files” online. The ultimate tool for generating an optimal my.cnf is not a tool. It’s a human with many years of experience, deep knowledge of MySQL and the full application stack, and familiarity with your application and your data. I don’t know […]

To find the bottleneck, stop guessing and start measuring

We recently examined a customer’s system to try to speed up an ETL (Extraction, Transformation and Loading) process for a big data set into a sort of datamart or DW.  What we typically do is ask customers to run the process in question, and then examine what’s happening.  In this case, the (very large, powerful) […]

Optimizing MySQL on Source Code Level

I’ve now added one more presentation to MySQL Performance Presentations page. This presentation is from MySQL Users Conference 2006 which was presented by Vadim but which we prepared together. Hope you enjoy it. Get it here