I've recently discovered a few things about how the mysql client library does things that seem a bit silly to me, so I'm going to share them with you.
- native prepared statements cannot take advantage of the query cache, resulting in lower performance.
- native prepared statements cannot execute certains types of queries, like "SHOW TABLES"
- native prepared statements don't correctly communicate column lengths for certain other "SHOW" queries, resulting in garbled results.
- calling stored procedures multiple times using native prepared statements causes the connection to drop.
I recommend that you use the following attribute when working with PDO::MYSQL, available in the current PHP 5.1.3 release candidates and snapshots:
$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
This causes the PDO native query parser to be used instead of the native prepared statements APIs in the mysql client, and effectively eliminates those problems.
I'll admit that the last point could well be a bug in my code; since I'll be at the MySQL Users Conference next week, I should be able to sit down with the right people and fix it.
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