Continuing on with the discussion on Waffle Grid, I have put together a few interesting benchmarks and wanted to expand on some of the possible deployment scenarios using Waffle.

My home laboratory is rather small, so my datasets are limited in size for the moment. To compensate I have shrunk the data sizes and database setting to simulate as best as I can the performance on a larger system. For this first test I decided to go with a 20 Warehouse DBT2 test, which equates to about 3GB of data in the database. In order to get a better feel for the performance benefit of fitting all most of your data in local memory + remote I setup my local machine with 768M allocated to the innodb buffer pool, and setup a remote machine with 768M allocated to memcached. This should scale up at a somewhat similar rate. What I mean by this is the increase seen with a 3GB dataset with 768/768 local/remote split I should also see with a 6GB dataset with a …

In a nutshell, there is some code for doing delayed replication from inside the server, as an optional parameter to the CHANGE MASTER TO syntax. Maatkit has a script for doing this functionally externally, but an internal solution might be preferred.

If you have an urgent interest in this feature, in either MySQL 5.0 or MySQL 5.1, please contact me to discuss.

See https://bugs.launchpad.net/ourdelta/+bug/288898 for more details and current code status (link to relevant OurDelta branch that has the work-in-progress patches).

The MySQL Enterprise Monitor continuously monitors MySQL servers and alerts to potential problems before they impact the system. It helps eliminating security vulnerabilities, improves replication, optimizes performance, and more. Its newest feature, Quan (Query Analyzer), helps identify queries that could be tuned to improve performance. Quan enables database administrators to do the work that would otherwise require hours in just minutes, or even seconds, and it provides ongoing statistical information about the performance of your queries.

MySQL Enterprise Monitor is a commercial offering by Sun Microsystems, and so was the documentation. To help anyone (even if they're not customers) get a better and complete understanding of what exactly MySQL Enterprise Monitor is about and what it can do, we've decided to make its full documentation publicly available. This has been done now, and the docs are part of the MySQL Manual now; see: …

Wikipedia is one of the world's most visited web sites (8th in the top 10, in fact), delivering an enormous breadth of content to an audience as vast as the internet.

But Wikipedia's evolved to become more than an on-line encyclopedia: they've become one of the world's largest search engines, they're a global source of real-time news, alongisde educational, political and health related content - and one of the world's most valuable brands and media properties.

Wikipedia's also a great example of a "redshift" application: a segment of the market that's growing faster than the technology industry's capacity to innovate. Technology companies have to pay special attention to such …

Q&A with Bruce Eckel, author of "Thinking in Java" READ MORE

Hi all,

Today I'd like to continue a blog series in which I highlight Web application tutorials for NetBeans 6.5. A few changes have been made to tutorials, among which is the featuring of MySQL as the database of choice.

This second entry in the series will cover the tutorial, "Creating an Ajax Application with Script.aculo.us", which is based on a blog entry by Arun Gupta.

This tutorial demonstrates the usage of the Java Persistence APIs to implement server side pagination (recommended for large sets of data) and to get and display the results in a text field featuring Ajax functionality. Ajax is a technology that combines (X)HTML, JavaScript, and CSS with the power of XmlHttpRequest in the creation of RIAs (Rich Internet Applications). Script.aculo.us is a set of JavaScript libraries to enhance the user …

If you have a slave, that slave is probably running with the read-only flag set in the mysqld-section of your my.cnf. To be able to write to a read-only slave you need to be the replication SQL_THREAD or have SUPER privilege.

Since 5.0.16, it is still possible to execute CREATE TEMPORARY TABLE on a read-only slave, so CREATE TEMPORARY TABLE privilege also allows you to write to a read-only slave in a limited and controlled way.

If you want to process a lot of data in a temporary table, you are probably creating the temporary table without any indices, then INSERT ... SELECT data into it, and then ALTER TABLE ... ADD INDEX afterwards, because that is usually faster than to insert data into a table with indices. Only that you cannot ALTER TABLE a temporary table, even on a server that is not read-only - in order to run ALTER TABLE on any table, even temporary onces, you need ALTER TABLE privilege which you might not want …

Do you read German? Then I have two recommendations for you.

First, go read this fresh interview with the German social networking guru Klaus Eck. It’s about “a life long job application process”.

Second, go read the book “Karrierefalle Internet” (”Career trap: Internet”) by Klaus Eck. That book is what the interview is all about.

Klaus Eck’s basic statement is “go manage your online reputation before others do it for you“. He notes that he’s seen plenty of Angst amongst …

Introduction

As it is known MySQL database server doesn’t have its own stored procedure debugging engine. Our company implemented custom debugging solution in dbForge for MySQL product line. And for new users it’s not always clear how it works. So we feel we need to clarify some aspects of implementation.

Here are common questions about debugging engine and answers to them.

What does ‘Deploy Debug Engine’ command do exactly?

Deploy Debug Engine command creates database named cr_debug with a set of stored procedures, functions and tables required for debugging.

To deploy debug engine your account needs to have PROCESS global privilege and the following privileges on cr_debug database (or global ones):

• SELECT
• CREATE
• DROP
• CREATE ROUTINE

What happens with procedure after executing ‘Compile …

I have written before - MyISAM Does Not Scale, or it does quite well - two main things stopping you is table locks and global mutex on the KeyCache.

Table Locks are not the issue for Read Only workload and write intensive workloads can be dealt with by using with many tables but Key Cache Mutex will still hunt you. If you aware of MySQL history you may think Key Cache scalability was fixed with new Key Cache in MySQL 4.1, and indeed previously it did not even scale with one CPU as global lock was held during IO duration, In MySQL 4.1 the lock is held only when key block (1KB to 4KB) is being copied from Key Cache to thread local buffer, which is terrible contention spot in particular on systems with many CPU cores.

Happily there is solution, or at least half of it.

If you have chosen a way of using …