Oracle 5.0, Reference Manual

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MySQL Native Driver (
Mysqlnd
)
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What it is not
Although MySQL Native Driver is written as a PHP extension, it is important to note that it does not
provide a new API to the PHP programmer. The programmer APIs for MySQL database connectivity
are provided by the MySQL extension,
mysqli
and PDO MYSQL. These extensions can now use the
services of MySQL Native Driver to communicate with the MySQL Server. Therefore, you should not
think of MySQL Native Driver as an API.
Why use it?
Using the MySQL Native Driver offers a number of advantages over using the MySQL Client Library.
The older MySQL Client Library was written by MySQL AB (now Oracle Corporation) and so was
released under the MySQL license. This ultimately led to MySQL support being disabled by default
in PHP. However, the MySQL Native Driver has been developed as part of the PHP project, and is
therefore released under the PHP license. This removes licensing issues that have been problematic in
the past.
Also, in the past, you needed to build the MySQL database extensions against a copy of the MySQL
Client Library. This typically meant you needed to have MySQL installed on a machine where you
were building the PHP source code. Also, when your PHP application was running, the MySQL
database extensions would call down to the MySQL Client library file at run time, so the file needed to
be installed on your system. With MySQL Native Driver that is no longer the case as it is included as
part of the standard distribution. So you do not need MySQL installed in order to build PHP or run PHP
database applications.
Because MySQL Native Driver is written as a PHP extension, it is tightly coupled to the workings of
PHP. This leads to gains in efficiency, especially when it comes to memory usage, as the driver uses
the PHP memory management system. It also supports the PHP memory limit. Using MySQL Native
Driver leads to comparable or better performance than using MySQL Client Library, it always ensures
the most efficient use of memory. One example of the memory efficiency is the fact that when using
the MySQL Client Library, each row is stored in memory twice, whereas with the MySQL Native Driver
each row is only stored once in memory.
Reporting memory usage
Because MySQL Native Driver uses the PHP memory management system, its
memory usage can be tracked with
memory_get_usage
. This is not possible
with libmysqlclient because it uses the C function malloc() instead.
Special features
MySQL Native Driver also provides some special features not available when the MySQL database
extensions use MySQL Client Library. These special features are listed below:
• Improved persistent connections
• The special function
mysqli_fetch_all
• Performance statistics calls:
mysqli_get_cache_stats
,
mysqli_get_client_stats
,
mysqli_get_connection_stats
The performance statistics facility can prove to be very useful in identifying performance bottlenecks.
MySQL Native Driver also allows for persistent connections when used with the
mysqli
extension.
SSL Support
MySQL Native Driver has supported SSL since PHP version 5.3.3
Compressed Protocol Support