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Search Results for: how to run more than one query in mysql 5.0

Is your server’s performance about to degrade?

I’ve been talking and writing a bit lately about the scaling problems I’m seeing on fast servers running lots of queries. As a rough guide, I’m seeing this in servers running 20k queries per second …


Introducing percona-patches for 5.1

Our patches for 5.0 have attracted significant interest.  You can read about SecondLife’s experience here, as well as what Flickr had to say on their blog.  The main improvements come in both performance gains and …


Upgrading MySQL

Upgrading MySQL Server is a very interesting task as you can approach it with so much different “depth”. For some this is 15 minutes job for others it is many month projects. Why is that …


table_cache negative scalability

Couple of months ago there was a post by FreshBooks on getting great performance improvements by lowering table_cache variable. So I decided to investigate what is really happening here. The “common sense” approach to tuning …


Innodb performance gotcha w Larger queries.

Couple of days ago I was looking for a way to improve update performance for the application and I was replacing single value UPDATE with multiple value REPLACE (though I also saw the same problem …


Impact of logging on MySQL’s performance

Introduction When people think about Percona’s microslow patch immediately a question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A …


Beware of MySQL Data Truncation

Here is nice gotcha which I’ve seen many times and which can cause just a minefield for many reasons. Lets say you had a system storing articles and you use article_id as unsigned int. As …


Profiling MySQL stored routines

These days I’m working with a customer who has an application based entirely on stored routines on MySQL side. Even though I haven’t worked much with stored procedures, I though it’s going to be a …


High-Performance Click Analysis with MySQL

We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work.  The first thing these have in common is that …


Computing 95 percentile in MySQL

When doing performance analyzes you often would want to see 95 percentile, 99 percentile and similar values. The “average” is the evil of performance optimization and often as helpful as “average patient temperature in the …