Some time ago I have shown that the proxy can do connection pooling and can keep server-side connections open to be reused by another client later. The keepalive tutorial shows how this can be implemented.

When it comes to reusing a server-connection for multiple client connections we have to face a small problem:

SQL connections aren't stateless (temporary tables, session variables, ...)

We have to handle this somehow.

When you use this feature the proxy will clean up for you by default, by issuing a COM_CHANGE_USER as the first command that is sent to the server. It basicly resets the connection and re-authenticates the user. You always get a clean environment and can't really tell that the server-side connection was open all the time.

But you don't really win performance either. A small benchmark shall give you an idea.

# connecting the client to the server ...
11:58:41.241956 …

Really often in customers' application we can see a huge tables with varchar/char fields, with small sets of possible values. These are "state", "gender", "status", "weapon_type", etc, etc. Frequently we suggest to change such fields to use ENUM column type, but is it really necessary (from performance standpoint)? In this post I'd like to present a small benchmark which shows MySQL performance when you use 3 different approaches: ENUM, VARCHAR and tinyint (+joined table) columns.

In practice you can also often use 4th variant which is not comparable directly, which is using integer value and having value mapping done on application level.

So, first of all, a few words about our data set we've used for this benchmark. We have 4 tables:
1) Table with ENUM:

PLAIN TEXT SQL:

1. CREATE TABLE cities_enum (
2.   id int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
…

Solid has released solidDB for MySQL 5.0.51-0081. There are a significant number of bug fixes in this release. For the full detailed list of bug fixes and enhancements, please see the ChangeLog. The download is at http://dev.soliddb.com/download

Jeff Gould has written an excellent piece on the big question arising from Sun's acquisition of MySQL: how will Sun make enough money on the deal to justify the $1 billion valuation? Gould's analysis is generally solid, but he misses a few key points.

First off:

Only time will tell. But in my humble opinion, MySQL's open source business model will make Sun's road to payback a lot steeper than if it had bought a software company with conventional revenues and profits.

Ah, the good old days! Just one problem: those days are gone. Pining for an acquisition of the old way of selling and distributing software is like pining for Mayberry: you can want it, but those days are never coming back. VCs aren't investing in proprietary Mayberry anymore. Except …

EXT3 has performance problems as the filesystem gets fragmented-although this is counter intuitive to the design of EXT3-fragmentation really happens.

Really there is no safe de-fragmenter tool out there for ext3. There is this one but I will not use it.

Fragmentation can get so bad that performance from EXT-3 can drop 7 fold!!

Here is some good info on fragmentation and a comparison of various other file systems.

Now for filefrag, I use this to see how bad an innodb file is fragmented.


TABLE.ibd: 4020 extents found, perfection would be 298 extents


Our wiz of a system administrator Kevin M., who I am teaching to become a mySQL DBA got me hooked on this utility: and he came up with a good …

This release contains bug fixes and new features. It also contains a new tool: my implementation of Paul Tuckfield's relay log pipelining idea. I have had quite a few responses to that blog post, and requests for the code. So I'm releasing it as part of Maatkit.

How To Install MySQL 4.1 And PHP4 On Debian Etch

MySQL 4 and PHP 4 are quite old, but you might have PHP applications on your server that require PHP4 and MySQL 4. The problem is that Debian Etch comes with MySQL 5 only, and its PHP4 packages depend on MySQL 5 and don't work with MySQL 4. This guide shows how you can install MySQL 4.1 on Debian Etch along with PHP4 packages that work with MySQL 4.1.

How To Install MySQL 4.1 And PHP4 On Debian Etch

MySQL 4 and PHP 4 are quite old, but you might have PHP applications on your server that require PHP4 and MySQL 4. The problem is that Debian Etch comes with MySQL 5 only, and its PHP4 packages depend on MySQL 5 and don't work with MySQL 4. This guide shows how you can install MySQL 4.1 on Debian Etch along with PHP4 packages that work with MySQL 4.1.

"sakila" is the sample database shipped with MySQL (pronounced as my ess-kew-ell). In the context of Sun Microsystems announcing the agreement to acquire MySQL, I'd like to dedicate this entry to show how this sample database can be exposed as a RESTful Web service endpoint and deployed on GlassFish using Jersey Tooling Plugin (0.4.1 with Jersey 0.4) in NetBeans IDE.

Lets get started!

1. Install MySQL & …

REvoltion Computing obtains funding. Fonality strikes deal with Dell for SMB telephony. SpringSource partners with Capgemini. (and more)

Intel Capital Makes Series A Investment in REvolution Computing, Intel Capital / REvolution Computing (Press Release)

SpringSource Announces Partnership with Capgemini, SpringSource / Capgemini (Press Release)

MuleSource Announces MuleCon 2008, MuleSource (Press Release)

GroundWork Open Source Appoints Tara Spalding as Vice President of Marketing, GroundWork Open Source (Press Release)

…