*edit* I want to point out that this test was done on a single database server which used MySQL partitioning. This is a demonstration of how Shard-Query can improve performance in non-sharded databases too.*edit*.

Over the weekend I spent a lot of time improving my new Shard-Query tool (code.google.com/p/shard-query) and the improvements can equate to big performance gains on partitioned data sets versus executing the query directly on MySQL.


I'll explain this graph below, but lower is better (response time) and Shard-Query is the red line.

MySQL understands that queries which access data in only certain partitions don't have to read the rest of the table. This partition elimination works well, but MySQL left a big optimization out of partitioning: …

InnoDB has an oft-unused parameter innodb_concurrency_tickets that seems widely misunderstood. From the docs: "The number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in a queue when it tries to enter InnoDB if the number of threads has already reached the concurrency limit. When a thread is allowed to enter InnoDB, it is given a number of “free tickets” equal to the value of innodb_concurrency_tickets, and the thread can enter and leave InnoDB freely until it has used up its tickets. After that point, the thread again becomes subject to the concurrency check (and possible queuing) the next time it tries to enter InnoDB. The default value is 500..."

What this means from a practical perspective is that each query is allocated 500 tickets when it begins executing. Each time it enters InnoDB, this number is decremented until it reaches zero ("entering InnoDB" …

With the help of the MySQL community leaders, ODTUG has embraced the opportunity to add MySQL content to the already jam-packed agenda at ODTUG Kaleidoscope 2010, in Washington, DC from June 27 – July 1.

This track starts on Monday, and will have presentations running the entire length of the conference. The track is highlighted by its participation in the Sundown Sessions with the Oracle ACE Directors. In this session, Sheeri K. Cabral and Ronald Bradford, two of the current three Oracle MySQL Ace Directors will host a …

Support for databases has generally been available only per server/year support contract where one has to pay for all master and slaves one has to get support contract for the few needed machines. In some cases one has even to pay per CPU (or core), even if you are not using all CPUs/cores for the database server. There have been a few exceptions, but there have usable been limits depending on company size or offerings that are only available for the first year.

What is wrong with server/year, for larger database installations is that you are also paying for database servers for which you don't need or want support. The value of the offering is thus worth much less than what you are paying for it.

The same way that MySQL® changed the price ballgame in licensing, Monty Program Ab is now doing the same for support with our newest offering; …

So I told myself "I wish I had a tool that installed plugins instantly and painlessly, the way MySQL Sandbox installs a server.
There you go. So yesterday I had enough of suffering and have put together an installation script that does a good job of installing several plugins with little or no effort.
OverviewHow does it work? For now, it's a separate script, but it will soon end into SBtool, the Sandbox tool.
Plugins need different operations, and the difficult part is finding a clear way of …

Prologue: Long back there were golden days of post graduation in the “great” DDIT (Now Dharamsinh Desai University), Nadiad. Assignments, termwork and journals or everything similar was in demand – I attempted a java code as my termwork on Monday, October 03, 2005. [That’s created date of .java file, I don’t remember anything.] A “variable […]

A new white paper is available from http://www.mysql.com/why-mysql/white-papers/mysql_wp_cluster_ScalingWebServices.php

MySQL and memcached has become, and will remain, the foundation for many dynamic web services with proven deployments in some of the largest and most prolific names on the web.

There are classes of web services however that are highly transactional and update-intensive, demanding real-time responsiveness and continuous availability. In these cases, MySQL Cluster provides the familiarity and ease-of-use of the regular MySQL Server, while delivering significantly higher levels of write performance with less complexity, lower latency and 99.999% availability.

This whitepaper will discuss the use-cases for both approaches, and provides an insight into how MySQL Cluster is enabling users to scale …

A new customer case-study is available for download from http://www.mysql.com/why-mysql/case-studies/mysql_cs-cluster_docudesk_WebServices.php

The DocQ web service eliminates the limitations of sharing physical documents by offering a complete paperless business solution; providing a single place where customers can manage, archive, and send their important documents. DocQ supports secure business transactions and the services to store, edit, collaborate, and publish business documents.

• The database needed to deliver the high levels of write throughput, low latency responsiveness and continuous availability …

It's taken almost 12 months, but I finally finished a CalDAV plugin for SabreDAV. I've stayed within the standard as much as possible, but had to leave out some features that failed to meet the cost/benefit requirement.

Most importantly, there's solid support for Apple iCal, Evolution, Lightning/Sunbird, and the iPhone.

It all uses PDO, and it's tested on both SQLite3 and MySQL.

SabreDAV is primarily intended as a toolkit to implement these protocols in different applications. Despite that, it should be reasonably easy to setup your own CalDAV server. …