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How to shrink the ibdata file by transporting tables with Trite
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You’ve probably had some troubles with the shared InnoDB tablespace stored in the ibdata file. Especially when it has grown for some reasons and reached a critical size.

This behavior occurs in some cases, due to excessive rollback segments growth or during a migration from a unique shared tablespace to a file-per-table configuration for example.

In this post, I would like to explain how to shrink the ibdata file after an unwanted file growth in a file-per-table configuration.
Note that the process could be done without Trite but the tool avoids to write the script used to transport tables yourself.

Initial situation


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Time to forget show processlist for monitoring?
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Disclaimer: I’m not specially an expert of benchmarking, this post is to compare different options. All comments and advices are welcome.

I’m not telling you anything new, the show processlist command is a fantastic command line tool for instant check.
But what about monitor your databases with this command embedded in a tool?

Just have a look at this graph:

With 5K queries per seconds, how much will be hidden with a show processlist executed every seconds? …


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[Tuto] A real life Multi-Master use case with MariaDB
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The goal of this tutorial is to show you how to use Multi-Master and aggregate databases with the same name but with different data from different masters.

Example:

  • master1 => a French subsidiary
  • master2 => a British subsidiary

Both have the same database (PRODUCTION) but the data are totally different:

We will start with 3 servers (2 masters and 1 slave), you can add more master if needed.

Informations

  •  10.10.16.231: first master (aka ”’master1”’) => a French …
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MySQL Connect 2013 Slides are available on [Plus]
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Hi,

You can find below the slides of the MySQL Connect 2013, enjoy!
(and much more in the slides page)

Why I do what I do?
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I was sincerely affected by this last MySQL post and this other very long post from Jeremy Cole.
Yes, these two guys are MySQL rock stars and they are really impressives, their involvement in the MySQL community is utter!

I don’t want to write a long long speech about my simple life…
I just want to clarify why I do what I do.

Many people have asked or wondered without asking why I do what I do
(Jeremy Cole - 2013)

A …



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An incomplete list of what your developers would like to know before migrating to MySQL 5.5
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A few years ago, I asked to check with me in the long (very long) change history of MySQL 5.5 documentation what are the changes in relation to the SQL syntax.
Chris Calender helped me to retrieve a list of the main changes, thanks again Chris.

Today, I would like to share this list with you.
It is simply a curated transcript of what you might find in the documentation but I’m sure it can help some of you.
 

INTO clause in nested SELECT statements

 
Previously, the parser accepted an INTO clause in nested SELECT statements, which is invalid …




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The strange commit behavior and the invisible Xid_log_event
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Did you see this when you are migrating from your lovely MySQL 5.1 to MySQL 5.5?
Oh, sorry, you remain attached to your pretty 4.1. Yes, I know, MyISAM has become so important in your life…

Ok, seriously, I would like to share this little observation I made recently when switching to MySQL 5.5 on one slave.
You can see below two graphs for the transactional activity, there is exactly the same volume of update, delete and insert queries :

MySQL 5.1

MySQL …



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An incomplete guide to linux system configuration for MySQL
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As a former Oracle DBA, I know how the system and the database are linked.
The first one who told me that the installation of Oracle has never been a problem is a liar!
Yes, your database and your system are the best of friends, you must respect that.

I’d make a list of linux system settings to configure a MySQL databases server and share my sources with you.
In return, I would like you to share your sources with the community by publishing your tips in the comments.

swappiness

 

  • This parameter allows to specify how the kernel must manage the memory swap



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Deploying remote MySQL sandboxes
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Stating the problem.

In my job, I do a lot of testing. And no matter how much organized we try to be, we end up with fewer machines than we would need to run all the tests that we want.

For some tasks, we can run MySQL Sandbox, and get the job done. But sometimes we need to make sure that applications and systems work well across the network, and we need to install and run systems on separate servers.

However, when you test replication systems, and every cluster takes three or four servers, you run our of available hosts very quickly. So you decide to use the clusters …

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Does MariaDB kill the magic query?!
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I’m sure that many of you use the magic query from Shlomi.
This query retrieves the difference between two status values with a single query.
I’m really fan of this kind of query and about this query in particular. This query is very useful to retrieve an information without to have to store a middle result.

Now, I tried this query on a MariaDB 5.5 server and I had a surprise :

The result was a bit strange, with …



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Showing entries 1 to 10 of 36 10 Older Entries

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