(Xaprb) If you’ve ever wished you could see MySQL’s EXPLAIN output formatted as a tree, now you can. MySQL Visual Explain transforms EXPLAIN output into a hierarchical view of the query plan, which is significantly easier to read and understand.

(Xaprb) Is your MySQL server doing an extra index scan on queries that need to check a key for matches or NULL? It’s easy for this to happen accidentally, but it’s also easy to fix, especially in MySQL 5.0 and up. Here’s how.

(Parvesh Garg) This is always mentioned that InnoDB is slower in giving results for COUNT(*) as compared to MyISAM. But as Peter points out in his blog that this fact only applies to COUNT(*) queries without WHERE clause. This text is from Peter’s blog only – “If you have query like SELECT COUNT(*)

(Jayant Kumar) Mysql 4+ has a feature known as query cache. Here mysql caches the result set. So suppose a query is run and it takes 5 seconds to run and query cache is enabled, so results are cached in the cache. Next time if the same query is run again (remember – exactly same query that is strcmp

(Ronald) While using the latest MySQL 5.1.20 yesterday I came across another situation that was not expected as with previous editions of MySQL. The background is experimenting with DRBD. When I configured MySQL to startup with a /etc/my.cnf file with data on a DRBD partition I got a failed startup

(Arjen Lentz) Scott Noyes wrote about a question frequently asked in for instance the freenode #mysql channel: given a table with students and answers, which students have answered all of a certain set of questions.

(Haidong Ji) A couple of weeks ago, a friend asked about replication on MySQL 4.1.7. I’ve worked with replication in the past, just a quick and dirty job on MySQL 5, and soon forgot about it. This time, I wanted to do it on MySQL 4, and make sure I take good notes for my own benefit. If it can […]

(Vikram Vaswani) If you’ve done any open-source database development recently, you probably already know that when it comes to selecting a database for your application, you have a plethora of choices. You are no longer limited to commercial products such as Microsoft SQL Server or Oracle; open-sour

(Giuseppe Maxia) The launch of MySQL Proxy has caused quite a commotion in the community. And with reason. For feature-hungry people, this is undeniably the most exciting addition to MySQL set of tools.

(Erik Wetterberg) Many times you need to produce XML output from your MySql database. MySql has no built-in support for creating XML in it’s SQL implementation but you can easily add support using the stored function feature.