MySQL

Using ROLLBACK with MyISAM

Using ROLLBACK with MyISAM is useless. A ROLLBACK command is used to undo any DML that occurs during a transaction (i.e. START TRANSACTION and COMMIT). The MySQL default storage engine MyISAM does not support transactions.

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How to find MySQL developers?

Brian wrote recently Where did all of the MySQL Developers Go? , while over in Drizzle land they have been accepted for the Google Summer of code along with many other open source projects.

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Understanding Drizzle user authentication options – Part 2

A key differentiator in Drizzle from it’s original MySQL roots is user based authentication. Gone is the host/user and schema/table/column model that was stored in the MyISAM based mysql.user table.

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Understanding Drizzle user authentication options – Part 1

A key differentiator in Drizzle from it’s original MySQL roots is user based authentication. Gone is the host/user and schema/table/column model that was stored in the MyISAM based mysql.user table.

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Using ext4 for MySQL

This week with a client I saw ext4 used for the first time on a production MySQL system which was running Ubuntu 9.10 (Karmic Koala) . I observe today while installing 9.

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Drizzle’s Data Dictionary and Global Status

With the recent news by Brian about the Data Dictionary in Drizzle replacing the INFORMATION_SCHEMA, I was looking into the server status variables (aka INFORMATION_SCHEMA.GLOBAL_STATUS) and I came across an interesting discovery.

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How do I identify the MySQL my.cnf file?

If you are unfamiliar in administrating MySQL, the current MySQL configuration file generally found is named my.cnf (my.ini on windows). Where is that file. If only that question was easy to answer!

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Don’t Assume – Per Session Buffers

MySQL has a number of global buffers, i.e. your SGA. There are also a number of per session/thread buffers that combined with other memory usage constitutes an unbounded PGA. One of the most common errors in mis-configured MySQL environments is the setting of the 4 primary per session buffers thinking they are global buffers.

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Free advice on your my.cnf

Today, while on IRC in #pentaho I came across a discussion and a published my.cnf. In this configuration I found some grossly incorrect values for per session buffers (see below).

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MySQL is crashing, what do I do?

Let me start by saying the majority of environments never experience problems of MySQL crashing. I have seen production environments up for years. On my own server I have seen 575 days of MySQL uptime and the problem was hardware, not MySQL.

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Advanced reporting options for MySQL

I’m seeking help from the MySQL community for what tools are used today to generate complex reports for enterprise applications that use MySQL. In an Oracle world, you have Oracle Report Writer , in Microsoft Crystal Reports .

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Migrating MySQL latin1 to utf8 – The process

Having covered the preparation and character set options of performing a latin1 to utf8 MySQL migration, just how do you perform the migration correctly. Example Case Just to recap, we have the following example table and data.

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Don’t Assume – Data Integrity

MySQL has the same level of data integrity for numbers and strings as Oracle; when MySQL is correctly configured. By default (a reason I wish I knew why it is still the default), MySQL performs silent conversions on boundary conditions of data that will result in your data not always being what is specified.

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How to crash mysqld intentionally

While some may think I’m daft, I have a legitimate reason for wanting to crash mysqld. However first we need to find a way to crash it. Great thanks to Alan K, Mark L, Harrison and Hartmut on #mysql-dev for several suggestions and a config option I was unaware of.

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