Many people have problem how to use the string data types (char/varchar) from the NDBAPI. Here I explain how you can use them.

First of all, let's create a table we can use as an example:

CREATE TABLE `t1` (
`a` int(11) NOT NULL,
`b` char(64) DEFAULT NULL,
`c` varchar(255) DEFAULT NULL,
`d` varchar(256) DEFAULT NULL,
PRIMARY KEY (`a`)
) ENGINE=ndbcluster DEFAULT CHARSET=latin1;


CHAR

In the MySQL server CHARs are space padded to the length of the CHAR.

Example:
insert into t1(a,b) values (1, 'mysql'); -- 'mysql' is 5 bytes long.

The MySQL server will now space-pad the string up to the length (in this case 64 bytes, given the character set used).

However, the NDBAPI does not respect this and does not care if it is space-padded, null-padded, or even 5-padded. But, if you want to be able …

SAN FRANCISCO ? Hyperic Inc., the leader in multi-platform, open-source IT management, today announced a technology license agreement with MySQL AB, the developer of the world?s most popular open source database. Under terms of the agreement, Hyperic?s SIGAR (System Information Gathering and Reporter) API is being incorporated into the new monitoring and advisory component of the recently-announced MySQL Enterprise subscription offering.

I will be a speaker at the Open Source Database Conference, which is held in Frankfurt from 6th to 8th November 2006, parallel to the International PHP conference.
I will present two sessions, one on Advanced Replication Techniques in MySQL 5 and the other on The MySQL General Purpose Stored Routines Library.
I submitted both proposals long before I started considering joining MySQL, so I will go there with the blessing of my current employer, but I will speak under my former affiliation, to avoid attributing to my current company what are my personal ideas.

There is a feature in MySQL to log all queries that take longer than long_query_time to execute, and optionally also log the queries that don't use indexes. If you are not familar with it, I recommend reading this page in our manual.

One issue to be aware of, is that some queries may take much longer than long_query_time to execute, but will not show up in your slow query log. The manual gives a very good explaination for this;

The time to acquire the initial table locks is not counted as execution time.

There are two status variables that may help in seeing if you are hitting read/write concurrency issues because of table-level locking;

mysql> show global status like 'Table_locks%';
+-----------------------+-------+
| Variable_name         | Value | …

Using freely available ZRM for MySQL , you can set up a solution to backup and restore your MySQL database, within minutes. This article has all the details.

If you're following MySQL or PHP landscape you should have seen announcement by MySQL to develop pure PHP driver. If not - Here is FAQ .

I'm to meet the team (Georg, Andrey etc) which will be developing this driver during my visit to Open Source Database Conference in November so I thought it would be good idea to gather some wish list for things nice to have in this new driver. Below is my list and I would appreciate to hear your ideas.

Build In Profiling I would like to see how many connections and queries page generated and how long they took - I will place this information in the log. For debugging I'd like to be able to get a table below page output listing all the queries, their exec times and number of rows they are returned. So far it has to be done in inherited class.

Auto Explain Would be very helpful for …

I have decided to withdraw definitively from the political debate on the European Patent Litigation Agreement (EPLA). The process itself may very well take several more years, but I will not do any more lobbying nor make any more public statements in this regard.

This year I made a lot of effort to inform politicians, the media and the public of the shortcomings of the present EPLA proposal, and I had the chance to make my contribution in the build-up to the European Parliament’s October 13 resolution, but I kept rather silent in recent weeks and will not speak out on this particular issue again. Until there is a new patent policy process in which I might participate, I will not comment on any patent-related issues. Last year I returned to the fray after three months of absence ? this time there definitely won’t be …

Ah well, since my first article on this, MySQL has had multiple version changes and I have gained more experience in using MySQL. (Off topic...... I really like the fact that I am stuck in everything from MySQL server config/support thru Apache thru WebObjects/Java development, deployment and administration ...... never a dull day in the job!). Here is my "new improved" process for setting up a replication master-slave configuration using MySQL 4.1.21. These instructions will definitely not work for version 4.0.XX and earlier and may not work for some earlier versions of 4.1. Earlier version incompatabilities are mostly related to the parameters used in mysqldump.

This article assumes a basic knowledge of unix (cd, ssh, scp, mkdir, chown) and a basic knowledge of mysql (mysqld, mysql, mysqldump, mysqladmin)

Ah well, since my first article on this, MySQL has had multiple version changes and I have gained more experience in using MySQL. (Off topic...... I really like the fact that I am stuck in everything from MySQL server config/support thru Apache thru WebObjects/Java development, deployment and administration ...... never a dull day in the job!). Here is my "new improved" process for setting up a replication master-slave configuration using MySQL 4.1.21. These instructions will definitely not work for version 4.0.XX and earlier and may not work for some earlier versions of 4.1. Earlier version incompatabilities are mostly related to the parameters used in mysqldump.

This article assumes a basic knowledge of unix (cd, ssh, scp, mkdir, chown) and a basic knowledge of mysql (mysqld, mysql, mysqldump, mysqladmin)

There are essentially two main choices for scaling MySQL - cluster (NDB) or replication.

For many people replication works fine because their application is mostly read based. Just throw a few MySQL slave servers into the mix and you can scale out pretty well.

My guess is that this only works well for about 80-90% of users.

You update your database on the master but perform queries on the slaves. If you need more queries you can just add more slaves.

The problem with replication is that you can't scale your writes. If you buy an expensive RAID array you can probably get 1500 transactions per second (maybe more) out of your IO array but that's the best you can do for the whole cluster.

As soon as you hit 100% of your transactions as writes you're done. You've hit a scaling wall with replication and you can't go any farther.

You can of course go with vertical replication partitioning which works …