Using a MySQL "HandlerSocket" plugin, Yoshinori Matsunobu achieved a 750K requests per second on a normal box, which was slightly more performant than with a memcached server
Maatkit is a package which contains high-quality command-line tools for MySQL. The tools enable power users of MySQL to do their work more safely and quickly by relying on tested software instead of scripting things themselves. The toolkit includes functionality such as table checksums, a query profiler, and a visual EXPLAIN tool, a multiprocess version of mysqldump.
"Jet Profiler for MySQL is real-time query performance and diagnostics tool for the MySQL database server". I love the Query ratings feature and the live query observation - should replace the weak use of MySQL proxy.
Sphinx is a standalone search engine, meant to provide fast, size-efficient and relevant fulltext search functions to other applications. Sphinx was specially designed to integrate well with SQL databases and scripting languages. Currently built-in data sources support fetching data either via direct connection to MySQL or PostgreSQL, or using XML pipe mechanism (a pipe to indexer in special XML-based format which Sphinx recognizes).
Consider the following pseudo-code:
$nid = node_save($data);
$node = node_load($nid);
Because node_save() executes a mutator query (an INSERT or UPDATE statement) is has to be executed on the master, so the master can propagate the changes to the slaves. Because node_load() uses a read-only query, it can go to the master or any of the available slaves. Because of the lack of synchronization between master and slaves, there is one obvious caveat: when we execute node_load() the slaves might not have been updated.
Securing plain text passwords in MySQL is NEVER a good idea. As a DBA you should take great care in protecting the users' information. Fortunately MySQL provides you with several options to protect passwords.
