A comparison of mysqlnd plugins with MySQL Proxy
MySQL Native Driver Plugin Architecture
MySQL Native Driver Plugin API
PHP Manual

## Obtaining the mysqlnd plugin API

The mysqlnd plugin API is simply part of the MySQL Native Driver PHP extension, ext/mysqlnd. Development started on the mysqlnd plugin API in December 2009. It is developed as part of the PHP source repository, and as such is available to the public either via Git, or through source snapshot downloads.

The following table shows PHP versions and the corresponding mysqlnd version contained within.

The bundled mysqlnd version per PHP release
PHP Version | MySQL Native Driver version
--- | ---
5.3.0 | 5.0.5
5.3.1 | 5.0.5
5.3.2 | 5.0.7
5.3.3 | 5.0.7
5.3.4 | 5.0.7

Plugin developers can determine the mysqlnd version through accessing MYSQLND_VERSION, which is a string of the format "mysqlnd 5.0.7-dev - 091210 - $Revision: 300535", or through MYSQLND_VERSION_ID, which is an integer such as 50007. Developers can calculate the version number as follows:

MYSQLND_VERSION_ID calculation table
Version (part) | Example
--- | ---
Major*10000 | 5*10000 = 50000
Minor*100 | 0*100 = 0
Patch | 7 = 7
MYSQLND_VERSION_ID | 50007

During development, developers should refer to the mysqlnd version number for compatibility and version tests, as several iterations of mysqlnd could occur during the lifetime of a PHP development branch with a single PHP version number.