It's been some time since I last blogged. I've been quite busy erasing all the
bugs from the partitioning implementation in MySQL 5.1. At the moment
there is 1 bug left in review and a few on its way into the main clone. The
rest of the bugs are fixed and already in the 5.1 clone. So the next 5.1
release (5.1.12) will have partitioning ready for tough tests. So if you have
been waiting for partitioning to stabilise it's time to try it out now with your
application and see how it works.
I watched an interesting animation my daughter made about how partition
pruning using dynamic PowerPoint slides. Really interesting to see what can
be done if one knows how to handle these types of tools. She's quickly
becoming our family authority on presentations.
Lately we've also started working on some extensions for the partitioning
hopefully ready for 5.2. We have introduced a new partitioning syntax like this:
CREATE TABLE t1 (a char(10), b date)
PARTITION BY RANGE (COLUMNS(b,a))
(PARTITION p0 VALUES LESS THAN ('1999-01-01', "abc"),
PARTITION p1 VALUES LESS THAN ('2001-01-01', MINVALUE),
PARTITION p2 VALUES LESS THAN ('2003-01-01', MAXVALUE));
The nice thing with this syntax is that it can be handled partition pruning with
ranges in a very efficient manner. So the query:
SELECT * FROM t1 WHERE b <= '1999-06-01' AND b >= '1999-02-01';
can be optimised to only scan partition p1.
We are also working on indexes that are partitioned independent of the base
table and also a couple of other features. As usual what actually goes into the
next release is uncertain.