We’re please to announce that the latest version of Kontrollbase is available. The most important part of this release is that the IE7 bugs have been fixed. There are a several other good changes too, which you can see in the change log. As per usual you can grab the download from our download page.

As I've wrote few times using multiple key caches is a great way to get CPU scalability if you're using MyISAM. It is however very annoying - this feature really looks half baked to me.

The problem with multiple key caches and mapping of tables to the different files is - there is no way to see the existing key caches, their mapping and stats. The only thing you can access is key cache parameters - via structured variables

In particular I would like to:

See the list of created caches Right now I can create key caches with random names causing invisible resource consumption. It is possible to make an error in key cache creation but it is not possible to later find out such key …

In benchmarks passion (see my two previous posts) I managed to setup all three devices (RAID was on board; Intel X25-E SSD connected to HighPoint controller, FusionIO card) on our working horse Dell PowerEdge R900 (btw, to do that I had to switch from CentOS 5.2 to Ubuntu 8.10, as CentOS was not able to start with attached SSD card to HighPoint controller) and along with other tests I ran tpcc-like IO-bound workload on all devices.

For tests I used MySQL 5.4/InnoDB, and all other parameters are the same from previous posts (100W, buffer_pool 3GB). Filesystem - XFS mounted with nobarrier option.

Graphical results are here

and average results:

RAID10 - 7439.850 TPM
SSD - 10681.050 TPM
FusionIO - 17372.250 TPM

However what should be noted - both SSD and FusionIO are run in "non-durable" mode, that is you may lose some transactions in …

From the MySQL User Conference in Santa Clara.

Konstantin Osipov + Peter Gulutzan’s presentation, “New Foreign Keys in 6.1″, is now available as an odp (Open Office presentation slides) file here. Nobody stomped out in a rage. One attendee said it’s a great development, he’s been waiting for years to see multi-storage-engine foreign keys. Another asked whether the feature would be in Drizzle, and Peter didn’t have the answer at the time, but later he asked a Drizzle worker and heard it’s improbable.

Peter heard a sideshow presenter suggest that the MySQL / DB2 storage engine was a surprise. The person didn’t allow time for questions or comments, but here’s a belated note that we sent out the first press release two years ago, …

As continue to my benchmarks http://www.mysqlperformanceblog.com/2009/04/30/looking-on-54-io-bound-benchmarks/ on 5.4 I tried in-memory load (basically changed buffer pool from 3GB to 15GB, and database size is 10GB). The results are on the same spreadsheet http://spreadsheets.google.com/ccc?key=rYZB2dd2j1pQsvWs2kFvTsg&hl=en#, page CPUBound.

I especially made short warmup (120 sec) and long run (2700sec) to see how different versions go through warmup stage.

The graph is

In default mode I would say XtraDB performs almost the same as 5.4, but dips are a bit worse than in 5.4.

Now about dips - all of them are caused by InnoDB checkpoint activity, InnoDB is doing intensive flushing of …

From the MySQL manual:
BIT_COUNT(N)

Returns the number of bits that are set in the argument N.

-------

I thought that meant that it returned the number of bits which needed to be set in order to store the value. To store 2^32 you need 33 bits of storage, with only one bit /set/. I expected 33 instead of 1.

#tested on 5.0.45 and 5.1.32-community
mysql> select i, pow(2,i), bit_count(pow(2,i)) from pow2;
+----+------------+---------------------+
| i  | pow(2,i)   | bit_count(pow(2,i)) |
+----+------------+---------------------+
|  1 |          2 |                   1 |
|  2 |          4 |                   1 |
|  3 |          8 |                   1 |
|  4 |         16 |                   1 |
|  5 |         32 |                   1 |
|  6 |         64 |                   1 |
|  7 |        128 |                   1 |
|  8 |        256 |                   1 |
|  9 |        512 | …

While at the MySQL Conference last week, I stopped at the booth for HeidiSQL, and spoke with Bill Culp, who is the developer of jHeidi, about Drizzle.

A few days ago, he emailed me, saying that he had spent the time, and now jHeidi supports Drizzle.

So now we have a multiplatform GUI for monitoring, browsing, and querying a Drizzle database server.

This edition of Log Buffer is my first article on the Pythian Blog. It seems appropriate that, as I start a new chapter of my life in Canada and am looking to the future, a lot of the blogs this week are doing the same.

After the shock of the Oracle takeover the MySQL community is full of hope. Mark Callaghan has written about the new storage engines for MySQL and also suggestions for what the MySQL community could be doing while they wait to hear what Oracle has planned.

Kaj Arno has looked to the future and he thinks he has found some answers.

With the …

Sheeri has informed us that MySQL Meetup.com account subscriptions have been expiring. I'm looking to see what's happening, please Don't Panic, I hope to have an answer early next week. As of now, we (Sun/MySQL) want and intend to keep the meetup.com subscriptions alive!

The answer is yes – kind of.

Stored procedures are implemented in a MySQL Server and can be used regardless of the storage engine being used for a specific table. One inference from this is that they won’t work when accessing the Cluster database directly through the NDB API.

This leads to the question of whether or not that limitation actually restricts what you can achieve. This article gives a brief introduction to stored procedures and looks at how the same results can be achieved using the NDB API.

Stored procedures provide a rudimentary way of implementing functionality within the database (rather than in the application code). They are implemented by the database designer and have the ability to perform computations as well as make changes to the data in the database. A typical use of stored procedures would be to control all access to the data by a user or application – for example, to impose extra checks on …