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SHOW OPEN TABLES – what is in your table cache

 | December 14, 2008 |  Posted In: Insight for DBAs

One command, which few people realize exists is SHOW OPEN TABLES – it allows you to examine what tables do you have open right now:

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Reading MySQL Enterprise future…

 | December 9, 2008 |  Posted In: Events and Announcements

Well, actually it is not reading future, but just mysql-5.1.30.rhel4.spec file from MySQL RedHat 4 SRPM. I found there few MySQL Enterprise Editions, namely: MySQL Enterprise Server – Advanced Edition MySQL Enterprise Server – Pro Edition MySQL Enterprise Server – Classic Edition What is difference ? Let’s see. For MySQL Enterprise Server – Advanced Edition: […]

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Computing 95 percentile in MySQL

 | November 28, 2008 |  Posted In: Insight for Developers

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 hospital”. Lets set you have 10000 page views or queries and have average response time of 1 second. What does […]

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Using INFORMATION_SCHEMA instead of shell scripting

 | November 24, 2008 |  Posted In: Insight for DBAs

INFORMATION_SCHEMA, in particular by favorite TABLES table is not only helpful to understand tables you have on the system, but I have also found it to be very helpful as a scripting language for variety of database administration tasks. It can be more straightforward compared to using shell or Perl when the operation is database […]

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Drilling down to the source of the problem

 | November 8, 2008 |  Posted In: Insight for Developers

I had an interesting tuning case few days ago. The system serving high traffic using Innodb tables would be stalling every so often causing even very simple queries both reads and writes taking long time to complete, with progress almost paused (dropping from thousands to tens of queries per second). On the surface the problem […]

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Fighting MySQL Replication Lag

 | September 22, 2008 |  Posted In: Insight for DBAs

The problem of MySQL Replication unable to catch up is quite common in MySQL world and in fact I already wrote about it. There are many aspects of managing mysql replication lag such as using proper hardware and configuring it properly. In this post I will just look at couple of query design mistakes which […]

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