To Emulate or Not to Emulate: When Should I Use PDO::ATTR_EMULATE_PREPARES?

The Use of PDO::ATTR_EMULATE_PREPARES: Performance and Security Considerations

PDO offers a flexible interface for interacting with databases, providing the option to emulate prepared statements using the PDO::ATTR_EMULATE_PREPARES attribute. This decision can impact performance and security.

Performance:

• Emulated prepared statements may offer slightly better performance when using the query cache in MySQL versions prior to 5.1.17.
• However, native prepared statements can leverage query plan caching, which may benefit overall execution time in certain scenarios.

Security:

• Native prepared statements do not significantly enhance security compared to emulated prepared statements.
• Both methods utilize parameter escaping to prevent SQL injection attacks.

Additional Considerations:

• Emulated prepared statements experience syntax errors at execution time, while native prepared statements display them at prepare time.
• Reusing prepared statement objects can improve performance compared to a single prepare/execute cycle.

Recommendation:

For older versions of MySQL (below 5.1.17), emulating prepared statements (PDO::ATTR_EMULATE_PREPARES = true) is recommended. However, for MySQL versions 5.1.17 and above, it is advisable to disable emulation (PDO::ATTR_EMULATE_PREPARES = false) for potential performance benefits.

Custom Connection Function:

To streamline the process, consider using a custom connection function that sets optimal PDO attributes, including PDO::ATTR_EMULATE_PREPARES, based on server version. For example:

function connect_PDO($settings) {
    $emulate_prepares_below_version = '5.1.17';

    // ... Code to connect and set options

    // Set prepared statement emulation depending on server version
    $serverversion = $dbh->getAttribute(PDO::ATTR_SERVER_VERSION);
    $emulate_prepares = (version_compare($serverversion, $emulate_prepares_below_version, '<'));
    $dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, $emulate_prepares);

    return $dbh;
}

By using such a function, you can optimize PDO settings for performance and security based on the specific MySQL version and application requirements.

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