Re: [PECL-DEV] mysqlnd_qc (mysqlnd query cache) 1.0.1 with prepared statement support

Benjamin Eberlei schrieb:
> How does PDO emulation of prepared statements affect the QC? Mysqlnd
> always gets the bound SQL statement? I.e. query cache always works?

PDO emulation uses plain vanilla queries to simulate a bind like API. 
The query cache can handle plain vanilla queries.

If you code looks like this, it can be cached already in the 1.0.0:

nixnutz@linux-fuxh:~/php/php-src/trunk_qc> sapi/cli/php -d 
mysqlnd.debug="d:t:O,/tmp/pdo.trace" -r 'var_dump(phpversion()); $pdo = 
new PDO("mysql:host=localhost;dbname=test", "root", "root"); $stmt = 
$pdo->prepare("SELECT 1 FROM DUAL LIMIT ?"); $stmt->execute(array(2)); 
var_dump($stmt->errorInfo());'

Of course the example lacks the SQL hints, uses a SQL statement with at 
least one column with an empty table name and so one but... given proper 
query and setup this can be cached in the 1.0.0 because PDO_MYSQL will 
not use a native prepared statement.

Therefore, the lack of support for native prepared statement in 1.0.0 
may be not that much of any issue for many.

That's why I wrote at 
http://docs.php.net/manual/en/mysqlnd-qc.basic_usage.php that PDO's 
prepared statements can be cached if PDO_ATTR_EMULATES_PREPARES = 1 
(which is the default).

Ulf