For the last few months I had quite a few MySQL blog posts and didn't have anything from my "new features in PHP [trunk|5.4]" series. This article is a bridge between those two. The PHP 5.4 NEWS file has a small entry:

MySQLi: Added iterator support in MySQLi. mysqli_result implements Traversable. (Andrey, Johannes)

From the outside it is a really small change and easy to miss. The mentioned class, mysqli_result, implements an interface which adds no new methods. What once can't see is that this relates to some internal C-level functions which can be called by the engine for doing a foreach iteration on objects of this class. So with PHP 5.4 you don't have to use an "ugly" while construct anymore to fetch rows from a mysqli result …

We have seen the "warning" against using MongoDB a few times now, and I have to say that this reminds me of other such warnings:

• 640 K is enough
  
• Relational databases are too slow (John Cullinane) (see for example: http://www.cbronline.com/news/ellison_makes_pre_emptive_strike_to_save_oracle_from_fate_of_cullinet)
• Linux is for nerds only.
• Virtual computing is waaay too slow.
• There is no reason anyone would want a computer in their home. (Ken Olsen, DEC)
• Who the h*ll wants to hear actors talk?. Warner

In a sense, most of them were right. If you had, in the 1920's, asked the movie going public if they wanted "talkies", chances are most of them would have said no. If you had told my mom and dad in the late 1970's …

If you are interested in NoSQL databases (or maybe not) perhaps you have seen the anonymous "warning" about using MongoDB.   It concludes with the following pious request:

  Please take this warning seriously.

Now there are a lot of great resources about data management on the web but the aforementioned rant is not one of them.  If you plan to write technical articles and have people take them seriously, here are a few tips.

1. Sign your name.  Readers are more impressed when they see you are not afraid to stand behind your words. 
2. Explain what problem you were trying to solve.  Otherwise uncharitable readers might think you just started pumping information into a new database without thinking about possible consequences and now want to blame somebody …

When we’re looking at benchmarks we typically run some stable workload and we run it in isolation – nothing else is happening on the system. This is not however how things happen in real world when we have significant variance in the load and many things can be happening concurrently.

It is very typical to hear complains about MySQL interactive performance – serving simple standard web traffic is drastically impacted when some heavy queries are ran in background or backup is done with mysqldump – a lot more than you would expect from simple resource competition. I finally found some time to look further in this problem and see what can be done to remedy it.

We designed the benchmark the following way – there is a small table (200MB) which completely fits in the Innodb Buffer Pool (512MB). We also have larger table 4GB which does not fit in the buffer pool. We’re running uniform sysbench OLTP on the …

Cold Case "DISABLE/ENABLE or REPLACE=UPDATE on Triggers"

The fact that MySQL is not supporting at his best triggers and Store Procedure, is something we all know quite well.

Because that, we normally do use them with caution, but the other day I was working on a simple action on a customer site, and I face something that I did not recognize immediately, because I was starting from a wrong assumption.

Let me describe the case. A customer needs to perform regular export of his data, and reload of it on a different site. To do that we put up an external procedure using "select into outfile" and "Load DATA in FILE".

Nothing special here.
Given we know what we were doing we also set the REPLACE or IGNORE keyword as manual: "The REPLACE and IGNORE keywords control handling of input rows that duplicate existing rows on unique key";

We disable UNIQUE and FOREIGN KEY checks as well, finally no replication …

In the lasts weeks, I choose to stay silent, to try to see and read other people blogs with a new eye. I was trying to go in depth of any single article, reading investigating and double-checking.

There were a lot of news and things going on, not all new and not all really interesting for me, but at the end, enough to le me say that I had spent many nights up reading and studying, instead leading ahead my own projects.

But what was surprise me as well, was that at the end what is very often interesting as a NEW feature or cool coming solution, it is not so interesting in the day by day work.

More what happens is sometime, or I should say too often, the new things that are cool development, are built on the rubble left behind.

Too often we have to still deal with annoying OLD bugs, or feature requests that are "by the facto" standard in almost all decent Database platforms.

Just in the last page (as for …

In the lasts weeks, I choose to stay silent, to try to see and read other people blogs with a new eye. I was trying to go in depth of any single article, reading investigating and double-checking.

There were a lot of news and things going on, not all new and not all really interesting for me, but at the end, enough to le me say that I had spent many nights up reading and studying, instead leading ahead my own projects.

But what was surprise me as well, was that at the end what is very often interesting as a NEW feature or cool coming solution, it is not so interesting in the day by day work.

More what happens is sometime, or I should say too often, the new things that are cool development, are built on the rubble left behind.

Too often we have to still deal with annoying OLD bugs, or feature requests that are "by the facto" standard in almost all decent Database platforms.

Just in the last page (as for …

Introduction

MySQL/Galera synchronous Multi-Master Replication consists of 2 parts:

• The wsrep patches for MySQL (codership-mysql) and
• the Galera Replication Plugin (galera).

If you do not want to download the prepared binaries you can build it on you own.

First you have to download the native MySQL sources, then patch it with the Galera wsrep patches and compile it. In a second step you have to build the Galera Plugin.

This is especially useful because in the standard Galera binary tar balls the garbd (and possibly other tools) is not provided.

The following steps describe how to do …

The MySQL documentation impresses me. I can’t recall a time when I didn’t find what I was looking for or that its details were lacking. Documenting a database server is difficult; the amount of information to organize and communicate clearly is staggering. I tasted that challenge when I helped update the Drizzle documentation, which was recently updated online.

I think Drizzle will become be a serious alternative or compliment to MySQL. Imho, Drizzle was until now held back by its documentation, or lack thereof, which created an insurmountable stumbling block for even clever DBAs. For example, Drizzle is largely comprised of plugins, but none of those plugins were documented until now.

I use the MySQL documentation as a goal, that to which the Drizzle documentation strives, not necessarily in style but in completeness. …

Topics for this podcast:

*Continuent extends MySQL replication to Oracle Database
*CFEngine updates server automation software
*Devops moving mainstream
*Neo Technology integrates with Spring
*451 CAOS report from Hadoop World

iTunes or direct download (26:56, 4.6MB)