http://www.php.net/manual/en/intro.mysqlnd-ms.php - Definitely has potential, makes me excited, but needs a bit more intelligent read/write splitting abilities, still.
http://mysqldba.blogspot.com/2012/02/asyncronous-shard-queries-in-php-using.html - some bits around asynchronous reads from a sharded set of databases.
http://dev.mysql.com/doc/refman/5.6/en/innodb-auto-increment-handling.html - Switching from MyISAM to InnoDB on some tables I have had to field a few questions from perplexed developers around their auto-increment values. Sometimes there are massive gaps now. Why? In part they are doing a lot of 'INSERT IGNORE' queries which effectively reserve an auto-inc value (unless you are specifying it manually) in the event they can insert. You don't get those back if the result is "ignore". You can, however, influence this a bit with the 'innodb_autoinc_lock_mode' variable. In short, you should not be relying on the auto-inc column being gap free.
http://www.percona.com/doc/percona-server/5.5/reliability/crash_resistant_replication.html - This one is fun. I have not benchmarked the cost of enabling this yet but I have experienced the problems it is trying to solve. Note that MySQL 5.6 also fixes this problem and the Percona 5.6 option is replaced by the Oracle MySQL solution.
Since it doesn't come up often I sometimes have to refer folks to this pretty good explanation and solution to the many-to-many relationship problem that isn't entirely valid in a normal RDBMS - http://www.tonymarston.net/php-mysql/many-to-many.html . Good read.
I have been conned into supporting PostgreSQL as well, lately. There is a bit to get used to like permissions. Permissions are wildly different and, I dare say, not well documented in the manual or many other places I found on the wide internet. Remember to grant usage on the schema itself when needed and remember to check for expired accounts. http://stackoverflow.com/questions/6799224/pgsql-grant-every-single-right-to-a-user-on-a-schema
http://www.tokutek.com/2011/07/indexing-the-director’s-cut/ - Note really a read so much as an excellent presentation. Make some popcorn, put it on the big-screen, enjoy.
http://www.npr.org/blogs/health/2013/07/18/203298244/worlds-biggest-virus-may-have-ancient-roots - Not related at all to databases, but still crazy cool.
http://www.oracle.com/us/corporate/press/1967380 - Yeah, it's Oracle, not MySQL but hey, they are doing some really nifty things, too. Pluggable (portable) databases, data heat-maps for auto-tiering storage, compression policies, detailed heuristics for index stats, and MapReduce features. I do always wish MySQL would do index stats more intelligently. For example, just because I have three possible values for a column doesn't mean 33% of the column is value 'a'.
Did I mention I passed the first part of the Oracle OCA exam? Yep, I now know the basics of Oracle SQL. It is, in a word, very different than MySQL SQL. So are many of the principles, like aliasing rules, whether or not you should use subqueries (obviously, the optimizer is a bit different, you can nest "unlimited" numbers of subqueries in some parts of the query and up to 256 deep in the where clause if you're crazy enough). Next step the actual Administration part. There is a lot of material for someone who doesn't use it hardly ever, but soon...
In case you have a lot to delete out of a very large table (let's just assume you "sharded it" or don't care and are trying to clean up old garbage) you may notice that a simple "DELETE FROM tbl WHERE col1='value';" is a bit too slow to be done in production, particularly with InnoDB if col1 isn't a primary key. Ideally, you want to do small, incremental deletes by primary key reference if possible to avoid hosing everything in the process. Here is a nice explanation of how to do it http://mysql.rjweb.org/doc.php/deletebig
Other neat things: https://code.google.com/p/flexviews/ and https://sdm.lbl.gov/fastbit/ and http://www.arubin.org/blog/2012/07/16/mysql-pam-ldap-authentication-module-configuration/ and https://github.com/mcafee/mysql-audit
I'll leave you searching for the reference with the following table, keeping in mind that one must never attempt to normalize Lewis Carroll:
CREATE TABLE OtherThings (
Speaker varchar(100) not null default "Walrus",
Listener varchar(100) not null default "Carpenter",
Topic enum('shoes', 'ships', 'sealing wax', 'cabbages', 'kings'),
SeaIsHost boolean,
PigsHaveWings boolean
) ENGINE=BLACKHOLE;
I'll try to pick a more particular topic for the next post...
